How to change display text of a Lookup field in Dynamics CRM using JavaScript

Description:
In this example we explain that ow to change display text of a Lookup field in Dynamic CRM using JavaScript. Or how to display Lookup Text instead of Default Field using JavaScript in Dynamic 365.or how to display related entity field in Lookup instead of the primary entity field in Dynamic CRM using JavaScript.

Generally, in Lookup when we open it displayed the primary field in Text after selection but our requirement was that to display other field in Lookup which is not PrimaryNameField.

Here we explain the Account lookup field that will by default display Account Name in Lookup because it is Primary Field Name now we want to display Account Number instead of the Account Name.

below is the JavaScript code that will help you to show or display Lookup Text as Account Number instead of Account Name in Dynamic CRM.You can call this function on the change of the Lookup field.

Code:

function ChangeLookUpDisplayValue(fieldname) {

            var lookupData = new Array();

            var lookupItem = new Object();

            var lookup = document.getElementById(fieldname);

            if (lookup != null && lookup.DataValue != null) {

                lookupItem.id = lookup.DataValue[0].id;

                lookupItem.typename = lookup.DataValue[0].typename;

                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>account</entityName>";

                xmlText += "<id>" + lookup.DataValue[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>accountnumber</b:string>";

                xmlText += "</a:Columns>";

                xmlText += "</columnSet>";

                xmlText += "</Retrieve>";

                xmlText += "</s:Body>";

                xmlText += "</s:Envelope>";

                var xHReq = new XMLHttpRequest();

                var url = Xrm.Page.context.getServerUrl() + "/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;

                    }

                }

            }

        }