< html >
< head >
< title >
test
</ title >
< script?language = " javascript " >

// var?select1_len?=?document.frm.s1.options.length;
var?select2? = ? new ?Array( 4 );


for ?(i = 0 ;?i < 4 ;?i ++ )?
{
?select2[i]? = ? new ?Array();
}
// 定義基本選項
select2[ 0 ][ 0 ]? = ? new ?Option( " 請選擇 " ,? " ? " );

select2[ 1 ][ 0 ]? = ? new ?Option( " PHP " ,? " ? " );
select2[ 1 ][ 1 ]? = ? new ?Option( " ASP " ,? " ? " );
select2[ 1 ][ 2 ]? = ? new ?Option( " JSP " ,? " ? " );

select2[ 2 ][ 0 ]? = ? new ?Option( " C/C++ " ,? " ? " );
select2[ 2 ][ 1 ]? = ? new ?Option( " Java " ,? " ? " );
select2[ 2 ][ 2 ]? = ? new ?Option( " C# " ,? " ? " );

select2[ 3 ][ 0 ]? = ? new ?Option( " Perl " ,? " ? " );
select2[ 3 ][ 1 ]? = ? new ?Option( " Ruby " ,? " ? " );
select2[ 3 ][ 2 ]? = ? new ?Option( " Python " ,? " ? " );


function?redirec(x)
{
?var?temp? = ?document.frm.s2;?
? for ?(i = 0 ;i < select2[x].length;i ++ )
? {
??temp.options[i] = new ?Option(select2[x][i].text,select2[x][i].value);
?}
?temp.options[ 0 ].selected = true ;

}
</ script >
</ head >
< body >
< form?name = " frm " >
< select?name = " s1 " ?onChange = " redirec(this.options.selectedIndex) " >
? < option?selected > 請選擇 </ option >
? < option?value = " 1 " > 腳本語言 </ option >
? < option?value = " 2 " > 高級語言 </ option >
? < option?value = " 3 " > 其他語言 </ option >
</ select >
< select?name = " s2 " >
? < option?value = " 請選擇 " ?selected > 請選擇 </ option >
</ select >
</ form >
</ body >
</ html >

JavaScript二級聯動下拉菜單