function verifyEmail(email){
var status = false;
var emailRegEx = /^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$/i;
     if (email.search(emailRegEx) != -1)
     {
          status = true;
     }
     return status;
}

function checkform(mf)
{
  var error='';
  if(mf.name.value=="")
  {
    error=error+" - Name is mandatory field. \n";
  }
  if(verifyEmail(mf.email.value)==false)
  {
    error=error+" - Email is mandatory field. \n";
  }
  if(mf.postcode1.value=="" && mf.airport1.value=="")
  {
    error=error+" - Pickup airport/postcode is mandatory field. \n";
  }
  if(mf.postcode1.value!="" && mf.airport1.value!="")
  {
    error=error+" - Pickup airport and postcode both selected. \n";
  }
  if(mf.postcode2.value=="" && mf.airport2.value=="")
  {
    error=error+" - Destination airport/postcode is mandatory field. \n";
  }
  if(mf.postcode2.value!="" && mf.airport2.value!="")
  {
    error=error+" - Destination airport and postcode both selected. \n";
  }
  if (error!="")
  {
    alert("Sorry, there are problems:\n"+error);
    return false;
  }
  else
  {
    return true;
  }
}