//specify speed of scroll (greater=faster)
var iSpeed=2;
var cSlowSpeed = 3;
var cFastSpeed = 7;
var contentHeight;

function scrollDown() {
	var oContent = document.getElementById('content');
	var iTop;
	if (window.moveUpVar) clearTimeout(moveUpVar)
	iTop = isNaN(parseInt(oContent.style.top)) ? 0 : parseInt(oContent.style.top);
	if (iTop >= (contentHeight*(-1)+400))
		oContent.style.top = iTop-iSpeed+"px";
	moveDownVar = setTimeout("scrollDown()",20);
}

function scrollDownSlow() {
	stopScroll();
	iSpeed = cSlowSpeed;
	scrollDown();
}

function scrollDownFast() {
	stopScroll();
	iSpeed = cFastSpeed;
	scrollDown();
}

function scrollUp() {
	var oContent = document.getElementById('content');
	var iTop;
	if (window.moveDownVar) clearTimeout(moveDownVar)
	iTop = isNaN(parseInt(oContent.style.top)) ? 0 : parseInt(oContent.style.top);
	if (iTop <= 0)
		oContent.style.top = iTop+iSpeed+"px";
	moveUpVar=setTimeout("scrollUp()",20); 
}

function scrollUpSlow() {
	stopScroll();
	iSpeed = cSlowSpeed;
	scrollUp();
}

function scrollUpFast() {
	stopScroll();
	iSpeed = cFastSpeed;
	scrollUp();
}

function stopScroll() {
	if (window.moveUpVar) clearTimeout(moveUpVar)
	if (window.moveDownVar) clearTimeout(moveDownVar)
}

function getcontent_height() {
	contentHeight = document.getElementById('content').offsetHeight;
}

function showPicture(oDiv) {
	var lcv;
	var oDivPhotoBy = document.getElementById('divPhotoCredit');
	var oImage = oDiv.getElementsByTagName('img')[0];
	var oNewImage = new Image();
	var oLargeImage = document.getElementById('imgPhotoLarge');
	var reImageSrc = /\/[a-zA-Z0-9\-]*\.jpg/;
	var aSpan = oDiv.getElementsByTagName('span');
	
	oNewImage.src = "portfolioPics" + reImageSrc.exec(oImage.src);
	oLargeImage.src = oNewImage.src;
	
	oDivPhotoBy.innerHTML = "&nbsp;";
	oLargeImage.alt = "";
	
	for (lcv=0; lcv < aSpan.length; lcv++) {
		switch (aSpan[lcv].className) {
			case "spnPhotoBy":
				oDivPhotoBy.innerHTML = aSpan[lcv].innerHTML;				
				break;
			case "spnAltTag":
				oLargeImage.alt = aSpan[lcv].innerHTML;
				break;
		}
	}

}