function EnableAjax(son, field)
{	
   	new Ajax.Request('/ajax_combo.asp?son=' + son + '&field=' + field + '&value=' + $(field).value,
  	{
   		method:'post',
	    onSuccess: function(transport)
	    {	
  			if (transport.responseText == "")
  			{
  				$(son).options.length = 1;
			}
			else
			{	
				var options = transport.responseText.split(';');
				$(son).options.length = options.length;
				for (var i = 0; i < options.length; i++)	
				{	
					var keyValue = options[i].split(',');
					var selected = (keyValue[0] == querySt(son));
					
					$(son).options[i + 1] = new Option(keyValue[1], keyValue[0], selected);
				}
			}
    	},
    	onFailure: function()
    	{
    		
    	}
	});
}

function querySt(ji) 
{
	hu = window.location.search.substring(1);
	gy = hu.split("&");
	for (i = 0; i < gy.length ; i++) 
	{
		ft = gy[i].split("=");
		if (ft[0].toLowerCase() == ji.toLowerCase()) 
		{
			return ft[1];
		}
	}
}