var popup = '';
function openWin(windowURL, windowName, windowFeatures) {
    closeWin();
    popup = window.open(windowURL, windowName, windowFeatures);
    if (popup) {
        popup.focus();
    }
}

function closeWin() {
    this.window.close();
}

function fillBack(field, text) {
    if(field.value == "") {
        field.value = text;
    }
}

function doBlink() {
	var blink = document.all.tags("BLINK")
	for (var i=0; i<blink.length; i++)
		blink[i].style.visibility = blink[i].style.visibility == "" ? "hidden" : "" 
}

function startBlink() {
	if (document.all)
		setInterval("doBlink()",1000)
}
window.onload = startBlink;

function clearError(id) {
    document.getElementById(id).style.visibility = "hidden";
}

function showError(id) {
    document.getElementById(id).style.visibility = "visible";
}
function warn(errors) {
    for (i = 0; i < errors.length; i++) {
        showError(errors[i]);
    }
}

        function checkForInvalidCharacters(strInput) {
            var invalidChars = "?&=";
            for (var i = 0; i < invalidChars.length; i++) {
                strBadChar = invalidChars.charAt(i);            //get next invalid character
                if (strInput.indexOf(strBadChar,0) > -1) return strBadChar;     //if there is one in Email
            }
            return "";
        }//checkForInvalidCharacters

        function checkContactForm() {
        var form = document.contact;
        var errorCount = 0;
        var errors = new Array();

        
        var alerts = '';
        var digits = "0123456789";
        var digitsandletters = "0123456789abcdefghijklmnopqrstuvwxyz";
        
        var fullNameError = "false";
        if (form.full_name.value == ""){
            alerts += "Please fill in your full name.\n";
            fullNameError = "true";
        }
        if (fullNameError == "true") {
            errors[errorCount] = "fullNameError";
            errorCount++;
        }
        
         var emailError = "false";
        if (form.email_addr.value == "") {
            alerts += "Please enter your email address.\n";
            emailError = "true";
        }
        if ( form.email_addr.value.indexOf("@")<1 && form.email_addr.value!="" ) {
            alerts += "Please verify that your email address contains the '@' sign.\n";
            emailError = "true";
        }
        if ( form.email_addr.value.indexOf(" ")>=0 && form.email_addr.value!="" ) {
            alerts += "Please verify that your email address does not contain any spaces.\n";
            emailError = "true";
        }
        if ((form.email_addr.value.indexOf ('@',0) == -1 ||
             form.email_addr.value.indexOf ('.',0) == -1) &&
             form.email_addr.value != "") {
            alerts += "Please verify that your email address is valid.\n";
            emailError = "true";
        }
        strBadChar = checkForInvalidCharacters(form.email_addr.value);
        if (strBadChar.length > 0) {
            alerts = alerts + "Email Address cannot include the " + strBadChar + " character.\n";
            emailError = "true";
        }
        if (emailError == "true") {
            errors[errorCount] = "emailError";
            errorCount++;
        }

        var subject  = form.subject.options[form.subject.selectedIndex].value;
        if (subject=="none"){
            alerts += "Please select subject from the drop-down list.\n";
            errors[errorCount] = "subjectError";
            errorCount++;
        }
        
        var commentsError = "false";
        if (form.comments.value == ""){
            alerts += "Please fill a comment.\n";
            commentsError = "true";
        }
        if (commentsError == "true") {
            errors[errorCount] = "commentsError";
            errorCount++;
        }
        
        if (alerts != ""){
            alert(alerts);
            warn(errors);
            return (false);
        } else {
            
            return (true);
        }
    }//checkContactForm()