jQuery: Test if checkbox is NOT checked

Question

I\'m having trouble figuring this out. I have two checkboxes (in the future will have more):

• checkSurfaceEnvironment-1
• checkSurface

Answer 1

Return true if all checbox are checked in a div

function all_checked (id_div){
 all_checked = true;

 $(id_div+' input[type="checkbox"]').each(function() { 
    all_checked = all_checked && $('this').prop('checked');
 }

 return all_checked;
}