Question

I need to catch the event where the columns are resized. How do I do that?

Answer 1

It seems to me you should use resizeStop event (see http://www.trirand.com/jqgridwiki/doku.php?id=wiki:events&s%5B%5D=resizeStop#list_of_events)

UPDATED:
After you resize a column header in the jqGrid it calls resizeStop event. For example

jQuery('#list').jqGrid({
    caption: 'My caption',
    url: myUrl,
    resizeStop: function (newwidth,index) {
      alert('Column #' + index + ' has now size ' + newwidth + ' px');
    },
    // other jqGrid parameters
});