alert error in sign-up form

[N Q H]

Hi all I have a form. In this form, there's a text box and a submit button. The problem is that I have to check what user puts to the text box before he can submit form. If the text box is blank I want to alert a error message(not a alert message) to the form. I intend to use a tag to block a error message. The code as bellow: function f_check() { //how to change the attribute <b>display:none</b> to <b>display:block</b> to show the message } Required Information Thanks in advanced [N][Q][H]

[Yusuf]

This should get you started. You need to clean up the code, for instance the toggle_visibility is not what you need.

function f_check()
{
var str = document.getElementById('txt_id').value;
if(str.length == 0)
toggle_visibility('span_id');
}

function toggle_visibility(id)
{
var e = document.getElementById(id);
if(e.style.display == 'block')
e.style.display = 'none';
else
e.style.display = 'block';
}

Yusuf Oh didn't you notice, analogous to square roots, they recently introduced rectangular, circular, and diamond roots to determine the size of the corresponding shapes when given the area. Luc Pattyn[^]