|
<HTML>
<HEAD>
<TITLE>Stacking up!</TITLE>
<SCRIPT>
var stack = new Array();
function pushStack(newVal) {
stack.push(newVal);
}
function popStack() {
var popVal = stack.pop();
if (popVal == undefined)
return "Empty stack!";
else
return popVal;
}
function showStack(theSelect){
theSelect.options.length = 0;
for (var i = 0; i < stack.length; i++){
var theOption = new Option(stack[i]);
theSelect.options[theSelect.options.length] = theOption;
}
}
</SCRIPT>
</HEAD>
<BODY>
<FORM>
<INPUT type=text name=txtPush>
<INPUT type=button value="Push" onClick='pushStack(txtPush.value); txtPush.value=""; showStack(theList);'>
<SELECT name="theList" size=12>
<OPTION>Displays the current state of the stack!
</SELECT>
<INPUT type=text name=txtPop size=25>
<INPUT type=button value="Pop" onClick="txtPop.value = popStack();
showStack(theList);">
</FORM>
</BODY>
</HTML>
|