Hallo !
Probier's doch mal so
<HTML>
<BODY>
<FORM>
<INPUT TYPE=BUTTON NAME="a" VALUE="Klick" STYLE="background-color: #FFFF66;" onClick="bla()"></BUTTON>
</FORM>
<SCRIPT>
function bla() {
alert("Guckuck!");
}
</SCRIPT>
</BODY>
</HTML>
Gruß
Hans