event.preventDefault() not working

Question

i have this line of code in my view using the Telerik Grid:

      columns.Bound(o => o.URI).Width(10).Sortable(false)
                .ClientTemplate("<A class='btnGrid' id=source<#= ID #> onclick=GridSelection.addItem('<#= ID #>') >Add</A>").Title("").Width(50);

the GridSelection addItem and disableSelected functions' JS codes:

  GridSelection = {
      addItem: function (value) {

         var anchorOption = $("a[id=source" + value + "]");

         anchorOption.click(function (e) { // variable name changed from "event"
               e.preventDefault();
               return false;    // as suggested by mr. Hamdi
               });

         anchorOption.fadeTo("slow", .5);

         GridSelection.disableSelected(anchorOption, true);

         var data = $("#GridSource").data('tGrid').data;
         var selectedObject;
         for (var item in data) {
            if (data[item].ID == value) {
               selectedObject = data[item];
               break;
            }
         }

          var grid = $("#GridSelected").data('tGrid');
          var newData = $("#GridSelected").data('tGrid').dataSource._data;
          newData.push(selectedObject);
          grid.dataBind(newData);
          grid.sort("");
          anchorOption.fadeTo("slow", .5);
      },

      disableSelected: function (element, disable) {
              //false on IEs 6, 7 and 8
              if (!$.support.leadingWhitespace) {
                  if (disable) {
                      $(element).attr('disabled', 'disabled');
                  } else {
                      $(element).removeAttr('disabled');
                  }
              }
     },
         // other GridSelection subfunctions here...

As I run the MVC3 web app in IE, it runs well because of the GridSelection.disableSelected function, but in Chrome and Mozilla Firefox, the event.preventDefault(); doesn't work. The anchor link still adds the data item even after the user has already added it there.

Is it OK having the preventDefault method inside the GridSelection.addItemfunction that was being prevented?

Which attribute is being prevented by the preventDefault , is it the href or is it the onclick?

What wrong with this? How can I fix this bug? Anyone who can help?