var found_error = false;

//:::::::::::::::::::::::::::::::::::::::::::::::::
function errors_found(error_msg){
	if (error_msg != '') {
		alert ("Please check the following errors:\n\n" + error_msg);
		found_error = false;
		return true;
	} else return false;
}

//:::::::::::::::::::::::::::::::::::::::::::::::::
function check_field(field_obj, field_desc, data_type, allow_null){
	var field_value = trim_field(field_obj);
	var error_msg = '';
	if (field_value.length==0) {
		if (!allow_null) error_msg = "- '" + field_desc + "' can not be empty.\n";
	} else if (((data_type=="INT") && !is_int(field_value)) || 
			 ((data_type=="FLOAT" || data_type=="REAL" || data_type=="CURRENCY") && !is_float(field_value)) ||
			 ((data_type=="EMAIL") && !is_email(field_value)) ||
			 ((data_type=="DIGITS") && !is_digit(field_value))) 
			 	error_msg = "- '" + field_desc + "' have a wrong format.\n";

	if (error_msg.length>0 && !found_error) {
		field_obj.focus();
		//field_obj.select();
		found_error = true;
	}	
	return error_msg;	
}

//:::::::::::::::::::::::::::::::::::::::::::::::::
function  trim_field(field_obj){
	var cleaned = trim(field_obj.value);
	field_obj.value = cleaned;
	return cleaned;
}

//:::::::::::::::::::::::::::::::::::::::::::::::::
function trim(value){
	var trimed = value;
	while((trimed.length > 0) && (trimed.indexOf(' ') == 0) )
		trimed = trimed.substr(1, trimed.length - 1);
	
	while((trimed.length > 0) && (trimed.lastIndexOf(' ') == trimed.length - 1))
		trimed = trimed.substr(0, trimed.length - 1);
	return trimed;
}

//:::::::::::::::::::::::::::::::::::::::::::::::::
function is_int(number){
  var num = parseInt(number);
  return (number == '' + num);
}

//:::::::::::::::::::::::::::::::::::::::::::::::::
function is_date(year, month, day){
  var check_date = new Date(parseInt(year), parseInt(month) - 1, parseInt(day));
  return( parseInt(day) == parseInt(check_date.getDate()) );
}

//:::::::::::::::::::::::::::::::::::::::::::::::::
function is_email(email){
   var pos = email.indexOf('@');
   return  !(pos<1 || pos==(email.length-1));
}

//:::::::::::::::::::::::::::::::::::::::::::::::::
function is_digit(number){
  var valid_digits= new String("01234567890");
  for (i=0; i<number.length; i++){
    if (valid_digits.indexOf(number.charAt(i))==-1) return false;
  }
  return true;
}

//:::::::::::::::::::::::::::::::::::::::::::::::::
function trim_zeros(str_num){
	var last_num= str_num.charAt(str_num.length-1);
	if (last_num=='.'){
		return str_num.substr(0,str_num.length-1);
	} else if (last_num!='0') {
		return str_num;
	} else {
		var new_num= str_num.substr(0,str_num.length-1);
		return trim_zeros(new_num);
	}	
}

//:::::::::::::::::::::::::::::::::::::::::::::::::
function is_float(number){
	var frm_num = number;
	if  (frm_num.charAt(0) == '.') frm_num = '0' + frm_num // start with . example .50
	var lastPoint = frm_num.lastIndexOf('.');
	if ( lastPoint>=0) { 
		var otherPoint = frm_num.lastIndexOf('.',lastPoint-1);
		if (otherPoint>=0) return false;	// another point, error!
		frm_num= trim_zeros(frm_num);  // trim al trailing zeros
	}	
	
	//-------------------------------------------------------
	var str_num = '' + parseFloat(number);
	var i
	for (i=str_num.length;i<frm_num.length;i++) str_num += '0' // case the user type 0000
	return (frm_num == str_num)
}