function isEmpty(name, num) {
	var result = null;

	if (num == null) {
		num = 0;
	}

  if (document.getElementsByName(name)[num].value == "") {
  	colorInvalid(name, num);
  	result = true;
  } else {
  	colorValid(name, num);
  	result = false;
  }  
  return result;
}

function isSelected(name, num) {
	var result = null;
	
	if (num == null) {
		num = 0;
	}
	
  if (document.getElementsByName(name)[num].options[0].selected) {
  	colorInvalid(name, num);
  	result = false;
  } else {
  	colorValid(name, num);
  	result = true;
  }  
  return result;
}

function isInt(name, num) {
	var result = null;
	
	if (num == null) {
		num = 0;
	}	
	
	if (isFinite(document.getElementsByName(name)[num].value) && document.getElementsByName(name)[num].value != "" && document.getElementsByName(name)[num].value >= 0) {
		colorValid(name, num);
		result = true;
	} else {
		colorInvalid(name, num);
		result = false;
	}
	return result;
}

function isDay(name, num) {
	var result = null;
	
	if (num == null) {
		num = 0;
	}	
	
	var day = document.getElementsByName(name)[num].value;
	
	if (day < 1 || day > 31 || !isFinite(day) || day == "") {
		colorInvalid(name, num);
		result = false;
	} else {
		colorValid(name, num);
		result = true;
	}
	return result;
}

function isMonth(name, num) {
	var result = null;
	
	if (num == null) {
		num = 0;
	}
	
	var month = document.getElementsByName(name)[num].value;
	
	if (month < 1 || month > 12 || !isFinite(month) || month == "") {
		colorInvalid(name, num);
		result = false;
	} else {
		colorValid(name, num);
		result = true;
	}
	return result;
}

function isYear(name, num) {
	var result = null;
	
	if (num == null) {
		num = 0;
	}	
	
	var year = document.getElementsByName(name)[num].value;
	
	if (year < 1800 || year > 2100 || !isFinite(year) || year == "") {
		colorInvalid(name, num);
		result = false;
	} else {
		colorValid(name, num);
		result = true;
	}
	return result;
}

function isHour(name, num) {
	var result = null;
	
	if (num == null) {
		num = 0;
	}	

	var hour = document.getElementsByName(name)[num].value;

	if (hour < 0 || hour > 23 || !isFinite(hour) || hour == "") {	
		colorInvalid(name, num);
		result = false;
	} else {
		colorValid(name, num);
		result = true;
	}
	return result;
}

function isMinute(name, num) {
	var result = null;

	if (num == null) {
		num = 0;
	}	
	
	var minute = document.getElementsByName(name)[num].value;
	
	if (minute < 0 || minute > 59 || !isFinite(minute) || minute == "") {
		colorInvalid(name, num);
		result = false;
	} else {
		colorValid(name, num);
		result = true;
	}
	return result;
}

function isColor(name, num) {
	var result = null;
	
	if (num == null) {
		num = 0;
	}	
	
	if (document.getElementsByName(name)[num].value.search(/^[\#]{1}[a-fA-F0-9]{6}/) == -1) {
		colorInvalid(name, num);
		result = false;
	} else {
		colorValid(name, num);
		result = true;
	}
	return result;
}

function isText(name, num) {
	var result = null;
	
	if (num == null) {
		num = 0;
	}	
	
	if (document.getElementsByName(name)[num].value.search(/^TEXT_[A-Z0-9]+/)) {
		colorInvalid(name, num);
		result = false;
	} else {
		colorValid(name, num);
		result = true;
	}
	return result;
}

function isEmail(name, num) {
	var result = null;
	
	if (num == null) {
		num = 0;
	}	
	
	if (document.getElementsByName(name)[num].value.search(/^[a-zA-Z0-9][\w\.-]*@(?:[a-zA-Z0-9][a-zA-Z0-9_-]+\.)+[A-Z,a-z]{2,5}$/) == -1) {
		colorInvalid(name, num);
		result = false;
	} else {
		colorValid(name, num);
		result = true;
	}
	return result;
}

function isDomain(name, num) {
	var result = null;
	
	if (num == null) {
		num = 0;
	}	
	
	if (document.getElementsByName(name)[num].value.search(/(?:[a-zA-Z0-9][a-zA-Z0-9_-]+\.)+[A-Z,a-z]{2,5}$/) == -1) {
		colorInvalid(name, num);
		result = false;
	} else {
		colorValid(name, num);
		result = true;
	}
	return result;
}

function isValidPath(name, num) {
	var result = null;
	
	if (num == null) {
		num = 0;
	}	
	
	if (navigator.userAgent.search(/Firefox\/3/) == -1) {	
		if (document.getElementsByName(name)[num].value.search(/^[a-zA-Z]{1}[\:]{1}[\\]{1}.*[\.]{1}[a-zA-Z]{3,4}$/) == -1) {
			colorInvalid(name, num);
			result = false;
		} else {
			colorValid(name, num);
			result = true;
		}
	} else {
		colorValid(name, num);
		result = true;
	}
	return result;
}

function isImg(name, sprache, num) {
  var result = false;
  var type = getImgType(name);
  var types = getImgTypes(sprache);
  
	if (num == null) {
		num = 0;
	}	  

  for (var i = 0; i < types.length; i++) {
  	if (type == types[i]) {
  		colorValid(name, num);
  		result = true;
			break;
  	}
	}	
  
  if (result === false) {
  	colorInvalid(name, num);
  }
  return result;
}

function isUrl(name, num) {	
	var result = null;
	
	if (num == null) {
		num = 0;
	}	
	
	if (document.getElementsByName(name)[num].value.search(/(http|https):\/\/(\w+:{0,1}\w*@)?(\S+)(:[0-9]+)?(\/|\/([\w#!:.?+=&%@!\-\/]))?/) == -1) {
		colorInvalid(name, num);
		result = false;
	} else {
		colorValid(name, num);
		result = true;
	}
	return result;	
}