function Evt_Snap_Point(interpolate_point)
{
    this._interpolate_point=interpolate_point;
}
Evt_Snap_Point.prototype=new Event();
Evt_Snap_Point.prototype.mouse_up=function(event)
{
    try{
        var geo=_MAP_WRAPPER.convert_to_geo(this._x_click,this._y_click);
        var action="snap";
        if(!this._interpolate_point)
            action="snap_on_exsisting_point";
			
        var params="type=snap_point&action="+action+"&layer_name="+_LAYER_SELECTED+"&x="+geo[0]+"&y="+geo[1];
        loading_message(true);
        process_ajax_call( params,_CNTR_GEOMETRIES_URL,
        function(error){
            if(!error)
            {
                clear_extra_graphics();
                var xml=this.responseXML;
                var x= new Number(xml.getElementsByTagName("x")[0].firstChild.nodeValue);
                var y= new Number(xml.getElementsByTagName("y")[0].firstChild.nodeValue);
                var p  = new Point(x,y);
                p._filled=false;
                _LIST_OF_EXTRA_GRAPHICS.push(p);
                _LIST_OF_POINTS.push(p);
                draw_extra_graphics(false);
                _OP_USER.do_operation_on_snapped(p);
                loading_message(false);
            }
            else
            {
                loading_message(false);
                return false;
            }
        } );
        stop_propagating_event(event);
    }catch(e)
    {
        alert("Evt_Snap_Point.mouse_up(): "+e);
        loading_message(false);
        return false;
    }	
};

Evt_Snap_Point.prototype.do_operation_on_snapped=function(point)
{
};