function validate_radio(field, alerttxt) {

	myOption = -1;
	for (i=field.length-1; i > -1; i--) {
		if (field[i].checked) {
			myOption = i; 
			i = -1;
		}
	}
	if (myOption == -1) {
		alert(alerttxt);
		return false;
	}
	else {
		return true;
	}	

}

function validate_jpg(field,alerttxt) {

	with (field){
		dotpos=value.lastIndexOf(".");
	        filetype=value.substring(dotpos).toLowerCase();
	        if ((filetype != ".jpg") && (filetype != ".jpeg")){
			alert(alerttxt + " Filtypen er " + filetype);
			return false;
		}
		else{
			return true;
		}
	}
}

function validate_required(field,alerttxt) {
	with (field) {
		if (value==null||value==""){
			alert(alerttxt);
			return false;
		}
		else {
			return true;
		}
	}
}

function validate_email(field,alerttxt) {
	with (field){
		apos=value.indexOf("@");
		dotpos=value.lastIndexOf(".");
		if (apos<1||dotpos-apos<2) {
			alert(alerttxt);
			return false;
		}
		else {
			return true;
		}
	}
}


function validate_numeric(field,alerttxt){
	var ValidChars = "0123456789.";
	var IsNumber=true;
	var Char;
	var sText = field.value;
 
	for (i = 0; i < sText.length && IsNumber == true; i++) { 
		Char = sText.charAt(i); 
		if (ValidChars.indexOf(Char) == -1) {
			alert(alerttxt);
         		IsNumber = false;
		}
	}
	return IsNumber;
}