// function: to clear text fields
function clearField(e) {
    if (e.defaultValue == e.value) {
        e.value = '';
    } 
    else if (e.value == '') {
        e.value = e.defaultValue;
    }
}

// function: validate submitted fields
function validate(){
    var error = false
	var errorMsg = ""
	
	// check data
	if ((document.getElementById("txtwish").value == "your anniversary wish goes here") || (document.getElementById("txtwish").value == "")) {
		error = true
		errorMsg += "Please provide your anniversary wish\n"
	}
	if ((document.getElementById("txtname").value == "name") || (document.getElementById("txtname").value == "")) {
		error = true
		errorMsg += "Please provide your name\n"
	}
	if ((document.getElementById("txtemail").value == "email") || (document.getElementById("txtemail").value == "") || (!isEmailValid(document.getElementById("txtemail").value))) {
		error = true
		errorMsg += "Please provide a valid email\n"
	}
	if (!error) {  //submit data
		return true
	} else {
		alert(errorMsg)
		return false
	}	
}

// function: toggles wish view
function toggleWishes(img){
    thisSrc = img.src
    if (thisSrc.indexOf("btnWishOver.gif") == -1) {	//swap
		document.getElementById("hidebtn").style.display='none'
		document.getElementById("hiddentxt").style.display='none'
		document.getElementById("wishbtn").style.display=''
		
	} else { //swap
		document.getElementById("wishbtn").style.display='none'
		document.getElementById("hiddentxt").style.display=''
		document.getElementById("hidebtn").style.display=''
	}
}

// function: validate email addres
function isEmailValid(str) {
	var at="@"
	var dot="."
	var lat=str.indexOf(at)
	var lstr=str.length
	var ldot=str.indexOf(dot)
	if (str.indexOf(at)==-1){
		return false
	}
	if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
		return false
	}
	if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
		return false
	}
	if (str.indexOf(at,(lat+1))!=-1){
		return false
	}
	if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
		return false
	}
	if (str.indexOf(dot,(lat+2))==-1){
		return false
	}
	if (str.indexOf(" ")!=-1){
		return false
	}
	return true					
}