How to change display text of a lookup field in Dynamics CRM 2011/13/15 using JavaScript

Usually when we select a value in a lookup field it displays the Primary Name Field in the text after selection. However it holds the PrimaryIDField in the background.

While working on a requirement a need arise to display a field in the LookUp display which is not a PrimaryNameField.

Let's consider the Order Lookup field here on Case Form. 

Requirement :


Display OrderNo in the display field instead of the OrderName (Which is a PrimaryNameField) in every Order Lookup.
(I have implemented this requirement in CRM 2015)

Before Using Javascript Lookup field Display text will look like below :

Javascript :

Pass Lookup Field as Parameter (I had passed "new_orderno" as fieldname parameter)

Put this Javascript on 'onchange' event of lookup field-

//Change Lookup Display Text

function ChangeLookUpDisplayValue(fieldname)
{
var lookupData = new Array();
var lookupItem= new Object(); 
var lookup = Xrm.Page.data.entity.attributes.get(fieldname);

if(lookup!=null)
{
var displayvalue='';
var xmlText='';

xmlText+="<s:Envelope xmlns:s=\"http://schemas.xmlsoap.org/soap/envelope/\">";xmlText+="<s:Body>";
xmlText+="<Retrieve xmlns=\"http://schemas.microsoft.com/xrm/2011/Contracts/Services\" xmlns:i=\"http://www.w3.org/2001/XMLSchema-instance\">";
xmlText+="<entityName>salesorder</entityName>";
xmlText+="<id>"+lookup.getValue()[0].id+"</id>";
xmlText+="<columnSet xmlns:a=\"http://schemas.microsoft.com/xrm/2011/Contracts\">";
xmlText+="<a:AllColumns>false</a:AllColumns>";
xmlText+="<a:Columns xmlns:b=\"http://schemas.microsoft.com/2003/10/Serialization/Arrays\">";
xmlText+="<b:string>ordernumber</b:string>";
xmlText+="</a:Columns>";
xmlText+="</columnSet>";
xmlText+="</Retrieve>";
xmlText+="</s:Body>";
xmlText+="</s:Envelope>";
var xHReq = new XMLHttpRequest();


var url=Xrm.Page.context.getClientUrl()+"/XRMServices/2011/Organization.svc/web";
xHReq.open("POST",url,false);
xHReq.setRequestHeader("SOAPAction","http://schemas.microsoft.com/xrm/2011/Contracts/Services/IOrganizationService/Retrieve");
xHReq.setRequestHeader("Content-Type", "text/xml; charset=utf-8");
xHReq.setRequestHeader("Accept","application/xml,text/xml,*/*");
xHReq.send(xmlText);

//Capture the result. 
var resultXml = xHReq.responseXML; 
var varray = new Array();

//Check for errors. 
var errorCount = resultXml.selectNodes('//s:Fault').length;
if(errorCount != 0) 
{
var msg = resultXml.selectSingleNode('//faultstring').nodeTypedValue;
alert(msg); 
}
else
{ 
var result = resultXml.getElementsByTagName("a:KeyValuePairOfstringanyType");
if(result.length>0) 
{
displayvalue= result[0].childNodes[1].lastChild.text;
}
if(displayvalue!='')       
{ 
lookupItem.name = displayvalue;
lookupData[0] = lookupItem;
lookup.DataValue = lookupData;
Xrm.Page.getAttribute("new_orderno").setValue([{id:lookup.getValue()[0].id,name:displayvalue,entityType:"salesorder"}]);
}
}
}
}

After Putting Above Javascript Lookup display text will look like below :

Hope this post will help someone who want to change Display Text of Lookup field.