struktur data stack

?html?
?head?
?title?Struktur Fata Stack?/title?
?script language = "JavaScript"?
var stack = new Array();

function Input_ke_Stack(data)
{
stack.push(data);
}

function Ambil_dari_Stack()
{
var data_dari_stack = stack.pop();
if(data_dari_stack == undefined)
return "Stack Sudah Kosong";
else
return data_dari_stack;
}

function TampilkanStack (list)
{
list.options.length = 0;
for (var i =0; i<>
{
var data = new Option (stack[i]);
list.options[list.options.length] = data;
}
}
?/script?
?/head?
?body?
?form?
?input type=text name=textSimpan?
?input type=button value="Masukan ke Stack"
onClick='Input_ke_Stack(textSimpan.value);
textSimpan.value="";
TampilkanStack(mediaList);'?
?select name="mediaList" size=12?
?option>Tampilan data....
?/select?
?input type=text name=textAmbil size=20?
?input type=button value="Ambil dari stack"
onClick="textAmbil.value=Ambil_dari_Stack();
TampilkanStack(mediaList);"?
?/form?
?/body?
?/html?