javascript in textarea

I am having trouble posting javascript code to a textarea. I am not sure what else I need to do.

<script language="javascript" runat="server">
...
</script>

Everything I post inside these tags does not display

I use a replace function also

tmessage = Replace(tmessage, "<", "<")
tmessage = Replace(tmessage, ">", ">")
tmessage = Replace(tmessage, """", """)

What else can I do?