Show the popup based on gridview row value in C#
I have gridview as followsSelectdata Studentid Name Month Sub1 Sub2 Sub3 Total
Checkbox 215 Ram Jan 50 80 70 200
Checkbox 123 Sam Jan 70 60 80 210
Checkbox 123 Sam Feb 50 80 75 205
Checkbox 150 Suresh Jan 70 80 90 240
i click the checkbox and click submit button if suppose any student id value appear more than once means i want to show the popup.
for example in the above gridview when i click the check box for the value student id 215 and click submit button pop up should not appear.
simliarily when i click the check box for the value student id 123 and click submit button i want to show the pop up for that how to do in c#