jQuery Grid Plugin - jqGrid

I have made a custom selection but it doesn't

work.

Here is the selection from teh database:

$SQL = "SELECT

c.soort,

c.kleur,

c.zesacht,

c.achttien,

c.tientwaalf,

c.twaalfviertien,

c.groter

FROM

invheader a, 

gladiolen c

WHERE

c.soort=c.soort ".$wh."

ORDER BY ".$sidx." ".$sord. "

 LIMIT ".$start." , ".$limit;

if I delete invheader a  the datagrid doesnt work

no data.

check http://www.egmondonline.furion.....qgrid.html

then go to demo there is a dynamical

dropdown too.

Please someone can help me?