<html> <head> <title>Javascript Form Validation</title> <script language='JavaScript' type='text/JavaScript'> <!-- function validate() { if(document.form1.textinput.value=='') { alert('Fill the Input box before submitting'); return false; } else { return true; } } //--> </script> </head> <body> <form name='form1' action='javascript_validation.php' method='post' onSubmit='return validate();'> Input :<input type=text name=textinput value=''> <input type=submit value=submit> </form> </body> </html>