Display Error if To month is less than From month in ASP.Net

if ((document.getElementById("monstart").value) > ((document.getElementById("monend").value))) { alert("Month To must be equal to or greater than FROM date!"); document.getElementById("monstart").select(); }

I am currently looking for a validation that will validate a month from and to, the value on the "monstart" and "monend" return it like this : August 2012 and July 2013, now i want to check if the month from is smaller than the month to. The code above does not validate. Can anyone help me with this please!!

Thanks in advance.