function checkCheckBox(f) {

 if (f.club.value=="") {
    alert('Please select club.');
    return false;
  } else

var minLength = 17; // Minimum length
if (minLength > f.vin.value.length ) 
{
alert('Your VIN number must be at least ' + minLength + ' characters long. Try again.');
return false;
  } else

if(f.color.value=="")
{
alert("Please enter your vehicle's color.");
return false;
  } else

if(f.model.value=="")
{
alert("Please select your vehicle's model.");
return false;
  } else


if(f.year.value=="")
{
alert("Please select your vehicle's year.");
return false;
  } else


if(f.number.value=="")
{
alert("Please select the number of Vipers you own.");
return false;
  } else


  if (f.agree.checked == false) {
    alert('Please agree to the terms and conditions to continue.');
    return false;
  } else
    return true;


}