Someone

function textelementchanged(input, name, aos, id) 
{
    var newval = input.value;
	if (input.defaultValue = input.value) {
	    var changes = document.getElementById("txtTrackChanges").value;
	        if (changes == "") {
            var changes =  " * " + name + " for Aos Period " + aos +  " changed to " + newval;
	        document.getElementById("txtTrackChanges").value =  changes;
	            if (document.getElementById("sess_txtKeyed_" + id).checked == true) {
	            alert("Changes is Blank, tick box is ticked");
	            document.getElementById("sess_txtKeyed_" + id).checked = unchecked;
	            }
	            else
	            {
	            alert("Changes is Blank, tick box is unticked");
	            }
	        }  
	        else
	        {
	        var changes = changes + "\n * " + name + " for Aos Period " + aos +  " changed to " + newval;
	        document.getElementById("txtTrackChanges").value =  changes;
	            if (document.getElementById("sess_txtKeyed_" + id).checked == true) {
	            alert("Changes is UnBlank, tick box is ticked");
	            document.getElementById("sess_txtKeyed_" + id).checked = unchecked;
	            }
	            else
	            {
	            alert("Changes is UnBlank, tick box is unticked");
	            }
	        } 
    }
	else 
	{
    }
}