Done..

Take Foyr textbox on the page... make one function "txtnull" and copy the code... ------------------------------------------------------------------ protected void Button1_Click(object sender, EventArgs e) { txtnull(); if (n == 4) { Response.Write("alert('Atleast one')"); return; } } int n = 0; private void txtnull() { if (TextBox1.Text == "") { n++; } if (TextBox2.Text == "") { n++; } if (TextBox3.Text == "") { n++; } if (TextBox4.Text == "") { n++; } } ------------------------------------------------------------------

You can use requiredfiledvalidator property of textboxex.

Your name:
Use the Textbox name as per ur project.