Open query !!!

[MFS]

Hello there.
I need help about opening query on edit click.
I have some datagrid where I recive some of data.All is ok.
But in query that qive me a data for datagrid I have two filds with a lot of data that I dont want to show in datagrid.
I want to show data only when i click on edit.
My question now is:
How to populate some of fields on edit form from other query.
First query for datagrid give to me all data that I want, but I cant in that query put and that two fields because is data in that fields to large and than datagrid is too slow.
My idea is, when I select some row and click edit, open form with data that I have in that grid but in that moment I want to open other query with param of that row that I clicked on and recive data from that new query and populate textboxs from that two fields with large data.
Any help???

My current code for call edit form:

Code:

		function PregledPrijava()
		{
			var row = $('#grdPregledPrijava').datagrid('getSelected');
			if (!row)
			{
				alert('Odaberite zapis koji želite pregledati.');
			}
			if (row)
			{
				$('#frmPregledPrijava').dialog('open').dialog('setTitle','Pregled prijave');
				$('#frmPregledPrijavaUnos').form('load',row);
			}
		}