function isFloat(curField, required, places,message){
	num = curField.value
	if((required)&&(num.length == 0)){
		alert (message)
		curField.select()
		curField.focus()
		return false
	}


	decimal = false
	for (i=0; i < num.length; i++){
		if ((num.charAt(i) < '0') || (num.charAt(i) > '9')){

			if ((num.charAt(i) != '.') || ((num.charAt(i) == '.') && (decimal))){
				curField.select()
				curField.focus()
				alert (message)
				return false
			}
			else{
				if ((num.length - i -1) > places){
					curField.select()
					curField.focus()
					alert (message)
					return false
				}					
				decimal = true
			}
		}
	}
	return true

}