Custom Lookup Salesforce

<apex:page standardController="Contact" extensions="MyCustomLookupController" id="Page" tabstyle="Contact">      <script type="text/javascript">     function openLookup(baseURL, width, modified, searchParam){      var originalbaseURL = baseURL;      var originalwidth = width;      var originalmodified = modified;      var originalsearchParam = searchParam;  alert(modified+'hello'+baseURL);      var lookupType = baseURL.substr(baseURL.length-3, 3);      if (modified == '1') baseURL = baseURL + searchParam;        var isCustomLookup = false;        // Following "001" is the lookup type for Account object so change this as per your standard or custom object      if(lookupType == "001"){          var urlArr = baseURL.split("&");        var txtId = '';        if(urlArr.length > 2) {          urlArr = urlArr[1].split('=');          txtId = urlArr[1];        }          // Following is the url of Custom Lookup page. You need to change that accordingly        baseURL = "/apex/CustomAccountLookup?txt=" + txtId;          // Following is the id of apex:form control "myForm". You need to change that accordingly        baseURL = baseURL + "&frm=" + escapeUTF("{!$Component.myForm}");        if (modified == '1') {          baseURL = baseURL + "&lksearch=" + searchParam;        }          // Following is the ID of inputField that is the lookup to be customized as custom lookup        if(txtId.indexOf('Account') > -1 ){          isCustomLookup = true;        }      }          if(isCustomLookup == true){        openPopup(baseURL, "lookup", 350, 480, "width="+width+",height=480,toolbar=no,status=no,directories=no,menubar=no,resizable=yes,scrollable=no", true);      }      else {        if (modified == '1') originalbaseURL = originalbaseURL + originalsearchParam;        openPopup(originalbaseURL, "lookup", 350, 480, "width="+originalwidth+",height=480,toolbar=no,status=no,directories=no,menubar=no,resizable=yes,scrollable=no", true);      }     }  </script>    <apex:sectionHeader title="Demo"  subtitle="Custom Lookup" />      <apex:form id="myForm">        <apex:PageBlock id="PageBlock">          <apex:pageBlockButtons >      <apex:commandButton action="{!Save}" value="Save"/>      </apex:pageBlockButtons>            <apex:pageBlockSection columns="1" title="Custom Lookup">        <apex:inputField value="{!Contact.LastName}"/>          <apex:inputField id="Account" value="{!contact.AccountId}"  />          <apex:inputField id="owner" value="{!contact.HR_Manager__c}"  />        </apex:pageBlockSection>      </apex:PageBlock>    </apex:form>    </apex:page>  ===========================

<apex:page controller="CustomAccountLookupController"      title="Search"     showHeader="false"     sideBar="false"     tabStyle="Account"     id="pg">      <apex:form >    <apex:outputPanel id="page" layout="block" style="margin:5px;padding:10px;padding-top:2px;">      <apex:tabPanel switchType="client" selectedTab="name1" id="tabbedPanel">          <!-- SEARCH TAB -->        <apex:tab label="Search" name="tab1" id="tabOne">            <apex:actionRegion >              <apex:outputPanel id="top" layout="block" style="margin:5px;padding:10px;padding-top:2px;">              <apex:outputLabel value="Search" style="font-weight:Bold;padding-right:10px;" for="txtSearch"/>              <apex:inputText id="txtSearch" value="{!searchString}" />                <span style="padding-left:5px"><apex:commandButton id="btnGo" value="Go" action="{!Search}" rerender="searchResults"></apex:commandButton></span>            </apex:outputPanel>              <apex:outputPanel id="pnlSearchResults" style="margin:10px;height:350px;overflow-Y:auto;" layout="block">              <apex:pageBlock id="searchResults">                 <apex:pageBlockTable value="{!results}" var="a" id="tblResults">                  <apex:column >                    <apex:facet name="header">                      <apex:outputPanel >Name</apex:outputPanel>                    </apex:facet>                     <apex:outputLink value="javascript:top.window.opener.lookupPick2('{!FormTag}','{!TextBox}_lkid','{!TextBox}','{!a.Id}','{!a.Name}', false)" rendered="{!NOT(ISNULL(a.Id))}">{!a.Name}</apex:outputLink>                       </apex:column>                </apex:pageBlockTable>              </apex:pageBlock>            </apex:outputPanel>          </apex:actionRegion>          </apex:tab>          <!-- NEW ACCOUNT TAB -->       <!-- <apex:tab label="New Account" name="tab2" id="tabTwo">            <apex:pageBlock id="newAccount" title="New Account" >              <apex:pageBlockButtons >              <apex:commandButton action="{!saveAccount}" value="Save"/>            </apex:pageBlockButtons>            <apex:pageMessages />              <apex:pageBlockSection columns="2">              <apex:repeat value="{!$ObjectType.Account.FieldSets.CustomAccountLookup}" var="f">                <apex:inputField value="{!Account[f]}"/>              </apex:repeat>            </apex:pageBlockSection>           </apex:pageBlock>          </apex:tab>-->      </apex:tabPanel>    </apex:outputPanel>    </apex:form>  </apex:page>
======================
public with sharing class MyCustomLookupController {
 private ApexPages.StandardController con; 
 public Contact contact {get;set;}
    public MyCustomLookupController(ApexPages.StandardController controller) {
    con=controller;
    contact = new Contact();
    }


  

  public MyCustomLookupController() {
    
  }
  
  public PageReference Save()
    {
   // con.save();
    ApexPages.StandardController c=new ApexPages.StandardController(contact );
    c.save();
    
    PageReference goTothis=new PageReference('/'+c.getId());
    goTothis.setRedirect(true);
    return goTothis;
    }
    

}
===============
public with sharing class CustomAccountLookupController {

  public Account account {get;set;} // new account to create
  public List<Account> results{get;set;} // search results
  public string searchString{get;set;} // search keyword

  public CustomAccountLookupController() {
    account = new Account();
    // get the current search string
    searchString = System.currentPageReference().getParameters().get('krishna');
    runSearch();  
  }

  // performs the keyword search
  public PageReference search() {
    runSearch();
    return null;
  }

  // prepare the query and issue the search command
  private void runSearch() {
    // TODO prepare query string for complex serarches & prevent injections
    results = performSearch(searchString);               
  } 

  // run the search and return the records found. 
  private List<Account> performSearch(string searchString) {

    String soql = 'select id, name from account ';
    if(searchString != '' && searchString != null)
      soql = soql +  ' where name LIKE \'%' + searchString +'%\'';
    soql = soql + ' limit 25';
    System.debug(soql);
    return database.query(soql); 

  }

  // save the new account record
  public PageReference saveAccount() {
    insert account;
    // reset the account
    account = new Account();
    return null;
  }

  // used by the visualforce page to send the link to the right dom element
  public string getFormTag() {
    return System.currentPageReference().getParameters().get('frm');
  }

  // used by the visualforce page to send the link to the right dom element for the text box
  public string getTextBox() {
    return System.currentPageReference().getParameters().get('txt');
  }

}