// This script validates input for the guestbook.

var requiredFields = new Array('FirstName','LastName','Email','Comment');
var fieldInfo = new Array();
fieldInfo['FirstName'] = 'First Name';
fieldInfo['LastName'] = 'Last Name';
fieldInfo['Email'] = 'Email Address';
fieldInfo['Comment'] = 'Comment for Guestbook';

function validateSubmit(nextAction) {
  var myAlertMsg = '';
  var thisForm = document.guestbookEntry;

  for (i=0; i<requiredFields.length; i++) {
    thisOb = thisField = thisForm.elements[requiredFields[i]];
    if (thisField.value == '') {
      myAlertMsg += '    '+fieldInfo[requiredFields[i]]+'\n';
      thisField.style.backgroundColor = '#ffaaaa';
    }
    else {
      thisField.style.backgroundColor = '#ffffff';
    }
  }

  if (myAlertMsg != '') {
    alert('You must fill out the fields labeled\n'+myAlertMsg);
  }
  else {
    thisForm.action.value = nextAction;
    thisForm.submit();
  }
}