Shell表单不能在JSFiddle上验证

Question

我之前见过这个问题。但是我还没有能够提出解决方案。我的表单不会在jsfiddle上验证它给我的shell表单错误任何想法？

http://jsfiddle.net/5jotjyq4/

提前致谢！

var error_count = 0;
//main validation function
function validation(form){

error_count = 0;

 var personalId = form.personal_id.value;
 var firstName = form.first_name.value;
 var lastName = form.last_name.value;
 var radio_length = form.sex.length;
 var checked="";

//check personal ID if empty 
if(personalId == "" ){
    error_code("personal_id");
}
else{
    resolved_code("personal_id");
}

//checks personal ID so only numbers are entered
if(!personalId.match(/^[0-9]+$/))
{
    error_code("personal_id");
}

//checks personal ID for 7 digits
if(personalId.length < 7)
{
    error_code("personal_id");
}
else{
    resolved_code("personal_id");
}

//checks first name input if empty
if(firstName == "" ){
    error_code("first_name");
}
else{
    resolved_code("first_name");
}

// if(firstName.match(/\s/){
//  document.getElementById("first_name").style.backgroundColor = "#FF4D4D";
//  error_count += 1;

// }


//check last name input if empty
if(lastName == "" ){
    error_code("last_name");
}
else{
    resolved_code("last_name");
}


//check to see if either radio button is checked
for(i=0; i<radio_length; i++)
{
    if(form.sex[i].checked)
    {
        checked = form.sex[i].value;
    }
}

if(checked == "")
{
    error_count++
    alert("Gender wasnt selected");
}



//functions to include code for error or resolved cases
function error_code(elem){
    document.getElementById(elem).style.backgroundColor = "#FF4D4D";
    error_count ++;
}

function resolved_code(elem){

    document.getElementById(elem).style.backgroundColor = "white";
}


if(error_count == 0){
    return true;
}
else{
    return false;
}