JavaScript IE vs JavaScript Chrome

IE works:

function validateMax2500Len(source, args) {


var x = (document.getElementById("txtDesc").value);

var l = document.getElementById("txtDesc").lastChild.length;

document.getElementById("lblLength").innerText = l;

if (x != "") {

if (l <= 100) { args.IsValid = true; }

else { args.IsValid = false; }

};

};   Chrome works:   function validateMax2500Len(source, args) {

var x = (document.getElementById("txtDesc").value);

var l = document.getElementById("txtDesc").value.length;

document.getElementById("lblLength").innerText = l;

if (x != "") {

if (l <= 100) { args.IsValid = true; }

else { args.IsValid = false; }

};

};