less than or equal to condition is not working in my script

<script type="text/javascript">
     function ValidateAddOnModule(source, args) {
         var gdv = document.getElementById('ContentPlaceHolder1_MainContent_grdAddonModules');

         var j = 0;
         var k = 0;
         for (var i = 1; i <= gdv.rows.length - 1; i++) {
             var img = document.getElementById('ContentPlaceHolder1_MainContent_grdAddonModules_ImgLanUserError_' + j);
             var LANUser = document.getElementById('ContentPlaceHolder1_MainContent_grdAddonModules_txtAdditionalLANUser_' + j).value;
             var MinLANUser = gdv.rows(i).cells(2).innerText;
            // alert(MinLANUser);
           //  alert(LANUser);
             if (MinLANUser != " ")
             {

                 if (MinLANUser <= LANUser) {
                     alert("true");
                     img.style.visibility = "hidden";
                 }
                 else {
                     alert("false");
                     img.style.visibility = "visible";
                     k = 1;
                 }
                 j++;
             }
         }


         if (k = 1) {
             return false;

         } else
         {

             return true;
         }


    }

</script>