function check_the_number() {

  /* Set whether to allow postive, negative or zero.
     Use the following values to set:
	 1 = Allow postive numbers (i.e 1, 15, 534, etc.)
	 2 = Allow positive numbers and zero (i.e. 0, 14, 235, 01, 0056 etc. )
  */	 
  var num_division = 1;
  
  if (document.getElementById && document.createTextNode) {	
    
	var the_num_OK = false; 
	var the_num_test = "";
	var the_num_err_msg = "";
	var the_num_err_extra = "";
    var the_num = document.getElementById("the_number").value;
	
	if (num_division == 1) {
		the_num_err_extra = "Only positive numbers are allowed";
		the_num_test = /^[1-9]{1}[0-9]*$/;
	   	the_num_OK = the_num_test.test(the_num);
	}
	else if (num_division == 2) {
		the_num_err_extra = "Only positive numbers and zero are allowed";
		the_num_test = /^[0-9]+$/;
	    the_num_OK = the_num_test.test(the_num);
	}
	else {
		window.alert("Cannot validate.");
		return false;	
	}
	
    if (the_num_OK) {
	  return true;	
	}
	else {
	    the_num_err_msg = "An ivalid number was entered. "+the_num_err_extra+" (no decimals).";
	    window.alert(the_num_err_msg);
	    return false;
	}
	
  }
  
}