Your code will not throw an exception if nothing is returned from the query, it simply won't display anything.
Try something like
if(objDT.Rows.Count == 0
MessageBox.Show(" No records found for this skills");
else
for (int i = 0; i < objDT.Rows.Count; i++)
{
... rest of your code
[Edit - a little more help on where that check could go]