Details:

1) FOR Input fields (INPUT[text], INPUT[password], INPUT[file], TEXTAREA) :
	L   	Required;
	L:>0	Required;
	L:=n	Must n characters;
	L:>n	At least n characters;
	L:<n	At most n characters;
	L:m-n	Must m to n characters;

2) FOR Select fields (INPUT[radio], INPUT[checkbox], SELECT) :
	L   	Must select;
	L:>0	Must select;
	L:=n	Must select n items;
	L:>n	At least select n items;
	L:<n	At most select n items;
	L:m-n	Must select m to n items;
	
3) FOR Content：
	C:id	Only by letters, numbers or underline;
	C:int	Only integer;
	C:num	Only numbers, decimal or negative;
	C:email	Check the email format;
	C:>n	Number of input MUST greater than n;
	C:<n	Number of input MUST less than n;
	C:m|n	Number of input MUST between m and n;
	
Example:

	------------------
	L,L:3-10,C:-4|100
	------------------

	"L" is Length;
	"C" is Content;
	For Input fields, "L" is characters's length;
	For Select fields, "L" is selected items's number;
	Separate statements by comma(,);
