function splitStringForItemX(stringToSplit,seperator,diffNum) {
  // splits a string into an array using the seperator
  // takes item itemX of this array and returns it
  arrayOfStrings = stringToSplit.split(seperator);
  var itemXNum = arrayOfStrings.length - diffNum;
  var itemX =  arrayOfStrings[itemXNum];
  return itemX;
}

function splitStringForLastItem(stringToSplit,seperator) {
  // splits a string into an array using the seperator
  // takes the last item of this array and returns it
  var arrayOfStrings = new Array();
  arrayOfStrings = stringToSplit.split(seperator);
  var lastItemNum = arrayOfStrings.length - 1;
  var lastItem =  arrayOfStrings[lastItemNum];
  return lastItem;
}

function splitStringForSecondLastItem(stringToSplit,seperator) {
  // splits a string into an array using the seperator
  // takes the second last item of this array and returns it
  var arrayOfStrings = new Array();
  arrayOfStrings = stringToSplit.split(seperator);
  var secondLastItemNum = arrayOfStrings.length - 2;
  var secondLastItem =  arrayOfStrings[secondLastItemNum];
  return secondLastItem;
}

function splitStringForFirstItem(stringToSplit,seperator) {
  // splits a string into an array using the seperator
  // takes the first item of this array and returns it
  var arrayOfStrings = new Array();
  arrayOfStrings = stringToSplit.split(seperator);
  var firstItem =  arrayOfStrings[0];
  return firstItem;
}

function check_num(the_input){
	var char_code = 0;
	var num_dot = 0;
	
	// to prevent entering anything other than numbers and decimal points
	for(i=0;i<the_input.length;i++){ 
		char_code = the_input.charCodeAt(i);
		if(((char_code < 48) && (char_code != 46)) || (char_code > 57)){
			alert(num_alert);
			break;
		}
		
		// to prevent entering more than 1 decimal points
		if(char_code == 46){ 
			num_dot++;
			if(num_dot > 1){
				alert(num_alert)
			}
		}
	}
}