ComboGrid select value and Ajax call

[Jakob]

I have a drop down field and when I select a value from drop down, an ajax call is made to submit the form

Code:

<script type="text/javascript">  
$(function(){
$('#comb').combogrid({  
    panelWidth:500,    
    url: 'myservice',  
    idField:'id',  
    textField:'desc'  
    columns: [[  
                {field:'Id',title:'Id',width:20},  
                {field:'desc',title:'Desc',width:80}
            ]],
    onSelect: function(index, row) {
   $.ajax({
                url: 'myjsp.jsp',
                method: 'GET',
                data: {
            val: row.dummy
            },
           success: function(response) {

        }
    });
}
});
});  

</script>

The problem is when I try to receive the value using request.getParameter value is null even though val is correctly passed as I can see header information like

Code:

out.println("value  "+request.getParameter("val"));%>

Why request.getParameter is null when ajax call is made?