JS warning example

Upload two warning images to the root path of the web project:

Check_error.gif

Check_right.gif

HtmlCode:

 
<Tr> <TD align = "right"> last name <font color = "red"> * </font> </TD> <TD width = "50%" align =" left "> <input name =" username "id =" username "type =" text "class =" text "onblur =" checkusername () "/> <span id =" warmusername "> </span> </TD> </tr>
 

JS Code:

// Verify the username function checkusername () {var username = $ ("input [name = 'username']"). val (); var Cu = document. getelementbyid ('warmusername'); If (username = "") {Cu. style. display = "NONE"; return true;} var unlen = username. replace (/[^ \ x00-\ xFF]/g ,"**"). length; If (unlen <3 | unlen> 15) {warning (Cu, unlen <3? 'User name cannot be less than 3 characters': 'user name cannot exceed 15 characters'); Return false;} Cu. style. display = ''; Cu. innerhtml = ''; return true ;}
 

 
Function Warning (OBJ, MSG) {obj. style. display = ''; obj. innerhtml = '' + MSG; obj. classname = "warning ";}
 

Style code:

 
. Warning {color: red; font-weight: bold ;}