function isPrefix(string1,string2) {
for(i=0;i<string1.length;++i)
	if(string1.charAt(i)!=string2.charAt(i)) {
		return false;
	}
	return true;
}

function checkUpgrade(theValue) {
	exampleKey1 = "*A 5BE2 3DED ED90 460F C7BD AF2A";
	exampleKey2 = "*A 5BE2 3DED ED90 460F C7BD AF2A ... *";
	exampleKey3 = "PAN0100005-BAT9-XR2Q-C3E4...";
	if (isPrefix(theValue,exampleKey1) || isPrefix(theValue,exampleKey2) || isPrefix(theValue,exampleKey3)) {
		alert("Please enter a valid license key in order to upgrade.");
		return false;
	}
	else if (theValue == "") {
		alert("You need to enter your license key!");
		return false;
	}
	else if (!isPrefix("*A ", theValue ) && !isPrefix("*B ", theValue ) && !isPrefix("*C ", theValue ) && !isPrefix("PEN01000", theValue ) && !isPrefix("PAN01000", theValue )) {
		alert("You need to enter a valid license key in order to update/upgrade.");
		return false;
	}
	return true;
}