easyUI的单元格添加点击触发事件

$(function() {
	$('#dtg_user').datagrid({
		columns : [ [ {
			title : 'c',
			field : 'c',
			width : 80,
			 formatter:function(value,rec){ 
				 	var c=rec.c;
	                var btn = '<a style="text-decoration:none" class="editcls" onclick="toPdf(\''+rec.c+'\')" href="javascript:void(0)">'+pOnumber+'</a>';  
	                return btn;  
	            } 
			
		}

<script>
function toPdf(c){
		alert(c);
}
</script>