Hi Hanifuk,
If you need to check if the user input is integer or not you can try this :
int i;
bool parsed = int.TryParse(Convert.ToString(textBox1.Text), out i);
if the value is integer the i variable will be set to the converted integer and the parsed boolean variable will be 'true'
else the i variable will be set to 0 and the parsed boolean variable will be 'false'
I hope this helps you,
:)