function DoSearch(obj)
{
    if(obj.tagName.toLowerCase()=="img")
    {
        window.location.href="/ProductList.aspx?key=name&value="+document.getElementById("txtProductName").value;
        return;
    }
    if(obj.tagName.toLowerCase()=="select")
    { 
        window.location.href="/ProductList.aspx?key=category&value="+obj.options[obj.selectedIndex].value;
        return;
    }
}