How to Control Fields

How may I control a form field that only could accept values from 00 to 99. Just this.

And I have two fields and both must be completed or filled to be proccesed, that mean you can't submit it without to complete both field.. how may I control this.

NVM

What language? PHP?

There are two times to check the value:
1. Before sending the form
2. After sending the form (when receiving it).

Before
Use Javascript to test the value:


After
You can't rely on Javascript alone. The visitor may have turned it off. Therefore you also have to check the values in your PHP script:




Implement a Javascript function both_fields_filled() to return true if both fields are filled, false otherwise. Then use

I could validate the forms, with this script, I just wanted control that nobody could submit a form with a blank form1.. this is the script..

<script>
<!--
function validate()
{
if (document.form1.valor.value=="")
{
alert ("Por favor introduzca el Valor de la Jugada")
return false
}
if (document.form1.numero.value=="")
{
alert ("Por favor introduzca el Número a Jugar")
return false
}
}
//-->
</script>

But I have a problem, it returns the Alert if it is blank, but when I submit the form it process a script an it run in the target='_blank', because I need it so.. but, if one the field of the form is blank it show the message, but doesn't return to the form, it continue, I need it stay in the form until the user complete the form..

Make sure that your form tag is as follows (as posted by md2perpe):



Note that you're returning the function return and not just running the function.

but the name of the Fuction is : check(), why I'm going to send to in the form,
form ... onsubmit="return both_fields_filled()">

I used

form ... onsubmit="check()">

The problem is, the validate script is ok, but, If I don't enter any data in one field it must stay in the same page, until you complete the form, it run the : form... action.php...

this is the site... prove it..
http://www.mailcreativo.com/loto/pale.php
click "enviar" without to fill any field...
I need to correct it...

If you don't use "return check()" the form doesn't evaluate the return value. It just executes the function and submits. If you return the function instead of just executing it, a false return will prevent the form from submitting and a true value will allow the form to submit. Try it.

Edit: I just saw that your problem wasn't necessarily with the return, but with the difference between check() and the function I referenced. My mistake. Try "return check()" and see if that works.