/* globals */
bName = navigator.appName;
bVer = parseInt(navigator.appVersion);

/* popbox vars */
popBoxWaitImage.src = "images/spinner40.gif";
popBoxRevertImage = "images/magminus.gif";
popBoxPopImage = "images/magplus.gif";
popBoxShowPopImage = true;
popBoxShowPopText = true;
popBoxShowRevertText = false;
popBoxShowCaption = false;

/* top menu nav */
if	(bName == "Netscape" && bVer >= 3) ver = "n3";
else if (bName == "Netscape" && bVer == 2) ver = "n2"; else if (bName == "Microsoft Internet Explorer" && bVer <= 3) ver = "e3"; else if (bName == "Microsoft Internet Explorer" && bVer >= 4) ver = "n3";

if (ver == "n3") {
	button1=new Image();
	button2=new Image();
	button3=new Image();
	button4=new Image();
	button5=new Image();
	
	button6=new Image();
	button7=new Image();
	button8=new Image();
	button9=new Image();
	button10=new Image();
	
	button1.src="images/home_on.jpg";
	button2.src="images/about_on.jpg";
	button3.src="images/instruments_on.jpg";
	button4.src="images/contact_on.jpg";
	
	button5.src="images/home_off.jpg";
	button6.src="images/about_off.jpg";
	button7.src="images/instruments_off.jpg";
	button8.src="images/contact_off.jpg";
}

function display(num) {
	if (ver == "n3")   {
	if (num=="1") document.home.src=button1.src;
	if (num=="2") document.about.src=button2.src;
	if (num=="3") document.instruments.src=button3.src;
	if (num=="4") document.contact.src=button4.src;
	
	if (num=="5") document.home.src=button5.src;
	if (num=="6") document.about.src=button6.src;
	if (num=="7") document.instruments.src=button7.src;
	if (num=="8") document.contact.src=button8.src;
	}
 }
 
 // input focus highlight
 function setHighlight(field, isEnabled){
    if(field){
        if(isEnabled == true){
            field.className = "highlight";
        }
        else{
            field.className = "";
        }
    }
}

// hide email error/success message
function hideEmailMsg() {
    document.getElementById("emailMsg").style.display = "none";
}

// check if field is empty
function isEmpty(field) {
    return ((field.value.length == 0 || field.value == null));
}

// check for valid email
function isValidEmail(field) {
    var filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
    if (!filter.test(field.value)) {
        return false;
    }
    
    return true;
}

// validate on submit
function validate() {
    var contactForm = document.contactUsForm;
    var errorMsg = '';
    var invalidElemCount = 0;
    
    for (var i = 0; i < contactForm.elements.length; i++){
        var elem = contactForm.elements[i];
        var invalidElem = false;
        
        if(elem.type == "text" ||  elem.type == "textarea"){
            // check empty fields
            if(isEmpty(elem)){
                errorMsg += "* " + elem.name + " cannot be blank.<br />";
                elem.style.borderColor = "#990000";
                invalidElem = true;
            }
            // check valid email
            else if(elem.name == "Email" && !isValidEmail(elem)){
                errorMsg += "* Email address is invalid.<br />";
                elem.style.borderColor = "#990000";
                invalidElem = true;
            }
            else {
                elem.style.borderColor = '';
            }
            
            if(invalidElem){
                // set focus to first invalid element
                if(invalidElemCount == 0){
                    elem.focus();
                }
                
                invalidElemCount++
            }
        }
    }
    
    if(errorMsg.length > 0){
        var validateDiv = document.getElementById('validateMsg');
        errorMsg = "Please correct the following errors before sending your message:<br /><br />" + errorMsg;
        validateDiv.innerHTML = errorMsg;
        validateDiv.style.display = "block";
        return false;
    }
    
    return true;
}