checking at least 3 checkboxes have checked

[i_am_james]

Hi

I have about 20 checkboxes on a register page for my site. I want to make sure that at least 3 of them have been checked. How would i go about doing this?

[mwasif]

If you have named them as checkbox_name[], then you can simply use

if(count($_POST["checkbox_name"])<3)
echo "please select atleast 3 checkbox"; 

[i_am_james]

How would I name them?

All i've got is:

Choose up to 3 genres which best suit you:*<br><br>

<input type="checkbox" name="rockcheck">Rock
<input type="checkbox" name="metalcheck">Metal

// etc...

[i_am_james]

Nevermind i've done it! Thanks for the reply!