function showDiv(id){
    if( document.getElementById(id).style.display == "block" ) document.getElementById(id).style.display = "none";
    else document.getElementById(id).style.display = "block";
}

function swapNews(show, hide){
    document.getElementById(show).style.display = "block";
    document.getElementById(hide).style.display = "none";
}

function showTabs(tab){
    switch( tab ){
        case "description":
            document.getElementById("features").style.display = "none";
            document.getElementById("specifications").style.display = "none";
            document.getElementById("features_a").className = "";
            document.getElementById("specifications_a").className = "";
            break;
        case "features":
            document.getElementById("description").style.display = "none";
            document.getElementById("specifications").style.display = "none";
            document.getElementById("description_a").className = "";
            document.getElementById("specifications_a").className = "";
            break;
        case "specifications":
            document.getElementById("description").style.display = "none";
            document.getElementById("features").style.display = "none";
            document.getElementById("description_a").className = "";
            document.getElementById("features_a").className = "";
            break;
    }
    document.getElementById(tab + "_a").className = "active";
    document.getElementById(tab).style.display = "block";
}

function toggleDivVis(id) {
	if (document.getElementById(id)) {
		if (document.getElementById(id).style.display == "block") {
			document.getElementById(id).style.display = "none";
		} else {
			document.getElementById(id).style.display = "block";
		}
	}
}

function checkContactForm() {
	var firstname = document.getElementById("txtFirstname").value;
	var lastname = document.getElementById("txtLastname").value;
	var company = document.getElementById("txtCompany").value;
	var email = document.getElementById("txtEmailAddress").value;
	var contact = document.getElementById("lstContactWho").value;
	var comment = document.getElementById("txtComment").value;
	

	if ( firstname!="" && lastname!="" && company!="" && email!="" && comment!="" ) {
		var mail_filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
		if( mail_filter.test(email) ) {
			return true;
		} else {
			alert("Invalid email address");
			return false;
		}
	} else {
		alert("Please fill in all the required fields before submitting your details.");
		return false;
	}
	
}

function openURL(url) {
	window.location.href=url;
}