Problem in Grid View

1) if you don't want to change value at dropdown value select than set the autopostback=false of dropdown box

2) for check box , store unique id of DB in on field or in hidden field,
than in rowcommand event iterate

foreach (GridViewRow grdRow in grd_name.Rows)
{
 CheckBox chk = (CheckBox)grdRow.FindControl("chk_checkbox");
 HiddenField hdn= (HiddenField)grdRow.FindControl("hiddenfiled");

 if (chk != null){
                        strids += hdn ",";
                        strstatus += Convert.ToInt32(chk.Checked).ToString() + ",";
           }
}

now you get the id string like 1,2,3,4,5 and
check box value as per id like true,false,false,true,false
etc.....

i think now u can understand what am i trying to say....
Thanks,,