Thank you Tony for replying and i am sorry i didn't notice your reply as i found a solution. Here is what i did.

i added below code in a function and called it when creating the dialog..

var rows = $j(“tr.jqgrow”, $table[0]);

for (var i = 0; i < rows.length; i++) {

var row_id_string = rows.id;

$j(“#” + row_id_string).attr('disabled', false);

$j(“#” + row_id_string, $table).addClass('enabled-background-color');

}

$table.jqGrid('resetSelection');

$table.jqGrid(“clearGridData”, true);