Validating a textbox in C#.net?

You can replace MessageBox with MessageBox.Show("Retry") to make the above statement work....however, its not going to be of much help to you. I was trying to focus you on how to capture the text from the textbox and then you can apply validations to it.

ive tried that but i get this error back now The name 'MessageBox' does not exist in the class or namespace 'WebApplication1.WebForm1' Thanks

thanks ill give it ago

Try capturing the text in the textbox and then add validation to it ---> string temp = textbox1.Text; if (temp == null) MessageBox("Retry"); Hope this helps!!