十种JavaScript事件处理的使用方法

1. onFocus：在用户为了输入而选择select、text、textarea等时

< html >

< head >

head >

< body >

< form  name ="test" >

< input  type ="text"  name ="userName"  value ="abc"  onFocus ="JavaScript:alert(document.test.userName.value);" >

form >

body >

html >

 
2. onBlur：在select、text、password、textarea失去焦点时

< html >

< head >

head >

< body >

< form  name ="test" >

< input  type ="text"  name ="userName"  value ="abc"  onblur ="JavaScript:alert(document.test.userName.value);" >



form >

body >

html >

3. onChange：在select、text、textarea的值被改变且失去焦点时

< html >

< head >

head >

< body >

< form  name ="test" >

< input  type ="text"  name ="userName"  value ="abc"  onChange ="JavaScript:alert(document.test.userName.value);" >

form >

body >

html >

4. onClick：在一个对象被鼠标点中时（button,checkbox,radio,link,reset,submit,text,textarea等）

< html >

< head >

head >

< body >

< img  src ="xsd.jpg"  onclick ="alert('ok');" > img >

body >

html >

5. onLoad：出现在一个文档完成对一个窗口的载入时

< html >

     < head >

     head >

     < body  onLoad ="javascript:alert('hello');"  onUnload ="javascript:alert('bye-bye');" >

        nihao

     body >

    

html >

6. onUnload：当用户退出一个文档时

< html >

     < head >

     head >

     < body  onLoad ="javascript:alert('hello');"  onUnload ="javascript:alert('bye-bye');" >

        nihao

    

     < form  name ="test" >

         < input  type ="text"  name ="t"  value ="hello"  onSelect ="javascript:alert('');" >

         < select  name ="se" >

             < option  value ="0" > hehe option >

             < option  value ="1" > hehe option >

         select >

     form >

     body >

html >

7. onMouseOver：鼠标被移动到一个对象上时

< html >

< head >

head >

< body >

< img  src ="xsd.jpg"  onmouseover ="alert('over')"  onmouseout ="alert('out')" > img >

body >

html >

8. onMouseOut：鼠标从一个对象上移开时
代码同上

9. onSelect：当form对象中的内容被选中时

< html >

< head >

head >

< body >

< form  name ="test" >

< input  type ="text"  name ="userName"  value ="SXT"  onSelect ="JavaScript:alert(document.test.userName.value);" >

form >

body >

html >

10. onSubmit：出现在用户通过提交按钮提交一个表单时

< html >

< head >

     < script  type ="text/javascript" > ...

        function check() ...{

            if(document.test.t.value == "") ...{

                alert("空值");

                return false;

            }

            return true;

        }

     script >

head >

< body >

< form  name ="test"  action ="1.htm"  onsubmit ="return check();" >

     < input  type ="text"  name ="t" >

< input  type ="submit"  value ="ok" >

form >

body >

html >