extensions/datagrid-filter.js - How to disable or remove a column?

[doev]

I try to remove all filterRules and set up the needed ones, but all filters are displayed:

Code:

$('#dg').datagrid('enableFilter');
$('#dg').datagrid('removeFilterRule');
$('#dg').datagrid('enableFilter', [{
	field:'listprice',
	type:'numberbox',
	options:{precision:1},
	op:['equal','notequal','less','greater']
}]);