Question

I have 3 inputs in a form. However when I serialize the data using funciton is() there is a 4th field found in the array at element 0. I can fix this by just looping starting at 1, but does anyone know what this is?

The debug output from IE looks like this

"undefinedf0a=on&f0b=&f0c="

for var b.

f0a, f0b, and f0c are my input names, “undefined” is the concern here.

function is(a)
  {
  var b;
  var c = document.forms[a].elements;   
  // test_input_signup(list)
  if(1)
    {
    for(i=0;i<c.length;i++) 
      {     
      b += c[i].name+"="+c[i].value+"&"; 
      }
      b = b.slice(0, -1)
    }
    return b;
  }

Answer 1

You need to initialize b to an empty string:

var b = '';