var reqcheck = 0;

function checkEmpty() {
    if (document.signin.elements['lastname'].value == "") {
        reqcheck++;
    }
    if (document.signin.elements['passwd'].value == "") {
        reqcheck++;
    }
    if (reqcheck > 0) {
        alert("\nPlease enter a last name and a password before submitting the form.");
        reqcheck = 0;
        return false;
    }
    else {
        return true;
    }
}

function disableMainTabs() {
	document.getElementById('aboutscectab').style.backgroundImage = "url('http://www.scec.org/redesign/gradDownBKGD.png')";
	document.getElementById('researchtab').style.backgroundImage = "url('http://www.scec.org/redesign/gradDownBKGD.png')";
	document.getElementById('resourcestab').style.backgroundImage = "url('http://www.scec.org/redesign/gradDownBKGD.png')";
	document.getElementById('educationtab').style.backgroundImage = "url('http://www.scec.org/redesign/gradDownBKGD.png')";
	document.getElementById('aboutscectab').style.borderWidth = "0px 0px 1px 0px";
	document.getElementById('researchtab').style.borderWidth = "0px 0px 1px 0px";
	document.getElementById('resourcestab').style.borderWidth = "0px 0px 1px 0px";
	document.getElementById('educationtab').style.borderWidth = "0px 0px 1px 0px";

	if(navigator.appName == "Microsoft Internet Explorer") {
		document.getElementById('aboutscectab').style.filter = "alpha(opacity = 75)";
		document.getElementById('researchtab').style.filter = "alpha(opacity = 75)";
		document.getElementById('resourcestab').style.filter = "alpha(opacity = 75)";
		document.getElementById('educationtab').style.filter = "alpha(opacity = 75)";
	} else {
		document.getElementById('aboutscectab').style.opacity = 0.8;
		document.getElementById('researchtab').style.opacity = 0.8;
		document.getElementById('resourcestab').style.opacity = 0.8;
		document.getElementById('educationtab').style.opacity = 0.8;
		
		document.getElementById('aboutscectab').style.MozOpacity = 0.8;
		document.getElementById('researchtab').style.MozOpacity = 0.8;
		document.getElementById('resourcestab').style.MozOpacity = 0.8;
		document.getElementById('educationtab').style.MozOpacity = 0.8;
	}
}

function tabs(txt) {
	disableMainTabs();
	
	if(document.getElementById(txt + 'tab')) {
		document.getElementById(txt + 'tab').style.backgroundImage = "url('http://www.scec.org/redesign/gradUpBKGD.png')";
		document.getElementById(txt + 'tab').style.borderWidth = "1px 1px 0px 1px";
		
		if(navigator.appName == "Microsoft Internet Explorer") {
			document.getElementById(txt + 'tab').style.filter = "alpha(opacity=100)";
		} else {
			document.getElementById(txt + 'tab').style.opacity = 1;
			document.getElementById(txt + 'tab').style.MozOpacity = 1;
		}
		
	}
	return txt;
}

function generateRandomBanner() {
	// Picks a random number from 0 to 10
	var randomNumber = (Math.random() * 11);
	randomNumber = Math.floor(randomNumber);
	randomNumber = (randomNumber % 11);
	
	// Then writes the banner that has that number
	document.write('<img src="http://www.scec.org/redesign/SCECbanner' + randomNumber + '.png" width="760" height="100" usemap="#banner" style="vertical-align: middle" border="0" />');
}

function generateRandomSmallBanner() {
	// Picks a random number from 0 to 10
	var randomNumber = (Math.random() * 11);
	randomNumber = Math.floor(randomNumber);
	randomNumber = (randomNumber % 11);
	
	// Then writes the banner that has that number
	document.write('<img src="http://www.scec.org/redesign/SCECbanner' + randomNumber + '.png" width="570" height="75" usemap="#banner" style="vertical-align: middle" border="0" />');
}


function generateRandomBannerImg() {
	// Picks a random number from 0 to 10
	var randomNumber = (Math.random() * 11);
	randomNumber = Math.floor(randomNumber);
	randomNumber = (randomNumber % 11);
	
	var imgSource = "http://www.scec.org/redesign/SCECbanner" + randomNumber + ".png";
	
	// Then writes the banner that has that number
	document.getElementById("banner").src = imgSource;
}