limiting number of checkboxes

babygodzilla

im using php and i have a form consisting of checkboxes. what is the best way of limiting the number of checkboxes a user can check? the problem is i never know how many checkboxes there will be. it could be 1 it could be 100. and since this is a search engine, the names of the checkboxes depend on the results. what i have right now is a javascript function that is called when a box is checked. it increments a variable and when it reaches 6 an alert will pop. im not sure why its not working.

function checkCount() {

var NewCount = 0

NewCount = NewCount + 1

if (NewCount == 6)
{
	alert('Pick 5 classes only')
	document.checks; 
	return false;
}
}

i actually got part of this code from a tutorial and it's supposed to work. but i'm thinkin that everytime this function is called, doesn't it set NewCount back to zero?

thanks!!!

tbach2

yer absolutely right. It resets the variable every time.

What you need to do is define the variable outside the javascript function, which will make it a global variable. (heheh, and don't reset it to zero in the function...)

Oh, and you might want to make a function that decrements it when an item is unchecked 😉

babygodzilla

ha! i knew i know SOME programming :p

i couldnt believe that guy made it work i dunno how...

thanks for the thing about decrementing it. that's a very good point 😃

so right now in the form i just have

<input type ='checkbox' name='$row[1]' onClick =  \"return checkCount()">

since i can never be sure of the checkbox's name, how do i make a conditional if its checked or unchecked? i thought of doing something like document.checks.(name).checked, cept i dunno the 'name'.

Weedpacket

Pass the checkbox to the function:

onClick =  "return checkCount(this)"

And in the function see if it's checked or not:

checkCount(checkbox)
{...
if(checkbox.checked)
...
}

or not - that will tell you the new state of the checkbox.

babygodzilla

got it, thanks!!

babygodzilla

is it possible to use a php variable as an form input value?

something like

echo"<td><input type ='checkbox' name='checks[]' value='$row[1]'

Moonglobe

ya but use {$row[1]}