function notNull(str){

	if (str.length == 0 )
		return false
	else{
		return true
	}
}  

function notBlank(str)	{

	for (i = 0; i < str.length; i++){

		if (str.charAt(i) != " ")
			return true
	}
	return false
}

function validateString(myfield, message){

	if (notNull(myfield.value)&& notBlank(myfield.value))
		return true
	else{
		alert(message )
		myfield.focus()
		return false
	}
}

function isNumber(myfield, message){

	str=myfield.value
	
	numdecs = 0;

	for (i = 0; i < str.length; i++){
		
		mychar = str.charAt(i)

		if ((mychar >= "0" && mychar <= "9")){			
			numdecs++
		}
		else if (mychar == "."){ 
			numdecs++
		}
		else{
			alert(message )
			myfield.value=''
			myfield.focus()			
			return false;
		}
	}
		
	return true
}