var objPopup;

function isEmail(val){
	regEmail = /^[\w-\.]+@[\w-]+([\.]?[\w-])+\.[a-zA-Z]{2,4}$/i;
	return regEmail.test(val);
}

function validateEmailField(field){
  if(isEmail(field.value)) {
    return true;
  } else {
    alert("You have entered an invalid email address. Please try again.");
    return false;
  }
}

function openWindow(filename, width, height){
	if(!objPopup || objPopup.closed){
		objPopup = window.open(filename, "popup", "width=" + width + ", height=" + height + ", left=15, top=15");
	}else{
		objPopup.focus();
		objPopup.location = filename;
	}
}

function openScrollWindow(filename, width, height){
	if(!objPopup || objPopup.closed){
		objPopup = window.open(filename, "popup", "width=" + width + ", height=" + height + ", left=15, top=15, scrollbars=1");
	}else{
		objPopup.focus();
		objPopup.location = filename;
	}
}