function opacity(id, opacStart, opacEnd, millisec) {
	//speed for each frame
	var speed = Math.round(millisec / 100);
	var timer = 0;
	
	changeOpac(opacStart,id);

	//determine the direction for the blending, if start and end are the same nothing happens
	if(opacStart > opacEnd) {
		for(i = opacStart; i >= opacEnd; i--) {
			setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
			timer++;
		}
	} else if(opacStart < opacEnd) {
		for(i = opacStart; i <= opacEnd; i++)
			{
			setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
			timer++;
		}
	}
}

//change the opacity for different browsers
function changeOpac(opacity, id) {
	var object = document.getElementById(id).style; 
	object.opacity = (opacity / 100);
	object.MozOpacity = (opacity / 100);
	object.KhtmlOpacity = (opacity / 100);
	object.filter = "alpha(opacity=" + opacity + ")";
}

function shiftOpacity(id, millisec) {
	//if an element is invisible, make it visible, else make it ivisible
	if(document.getElementById(id).style.opacity == 0) {
		opacity(id, 0, 100, millisec);
	} else {
		opacity(id, 100, 0, millisec);
	}
}

function blendimage(divid, imageid, imagefile, millisec) {
	var speed = Math.round(millisec / 100);
	var timer = 0;
	
	//set the current image as background
	document.getElementById(divid).style.backgroundImage = "url(" + document.getElementById(imageid).src + ")";
	
	//make image transparent
	changeOpac(0, imageid);
	
	//make new image
	document.getElementById(imageid).src = imagefile;

	//fade in image
	for(i = 0; i <= 100; i++) {
		setTimeout("changeOpac(" + i + ",'" + imageid + "')",(timer * speed));
		timer++;
	}
}

function currentOpac(id, opacEnd, millisec) {
	//standard opacity is 100
	var currentOpac = 100;
	
	//if the element has an opacity set, get it
	if(document.getElementById(id).style.opacity < 100) {
		currentOpac = document.getElementById(id).style.opacity * 100;
	}

	//call for the function that changes the opacity
	opacity(id, currentOpac, opacEnd, millisec)
}

function show(id) {
	var element = document.getElementById(id);
	element.style.display = "block";	
}

function hide(id) {
	var element = document.getElementById(id);
	element.style.display = "none";		
}

function validateForm(theForm) {

	var missingFields = "";
	
	missingFields += checkField(theForm["firstName"]);
	missingFields += checkField(theForm["lastName"]);
	missingFields += checkField(theForm["phoneNumber"]);
	missingFields += checkField(theForm["email"]);
	missingFields += checkField(theForm["dates"]);
	missingFields += checkField(theForm["numberOfAttendees"]);
	missingFields += checkField(theForm["purposeOfEvent"]);
	missingFields += checkField(theForm["timePreferred"]);
	
	if(missingFields != "") {
		document.getElementById("errorMsg").innerHTML = "You have not completed all required fields.";
		return false;
	}
	
	submitForm(theForm);
	

}

function submitForm(theForm) {
	if(arguments[1] == 'cancel') {
		hide('Popup');
		hide('PopupDisablePage');
	} else {
		theForm.submit();
	}
}

function checkField(Field) {
	
	var error = "";
	
	if (Field.value.length == 0) {
		Field.style.background = '#ffcccc'; 
		error = "error";
	} else {
		Field.style.background = 'White';
	 }
	 
	return error;
	
}