function jumpbox(Select){
     if (document.framecombo.choice[0].checked)
          parent.main.location.href = Select.options[Select.selectedIndex].value
     else open(Select.options[Select.selectedIndex].value)
}

</SCRIPT>

<FORM NAME="framecombo">
    <SELECT NAME="jump2" onChange="jumpbox(this)">
        <OPTION VALUE="main.htm">Go To</OPTION>
        <OPTION VALUE="http://espn.go.com">ESPN Sports</OPTION>
        <OPTION VALUE="http://microsoft.com">Microsoft</OPTION>
        <OPTION VALUE="http://www.allaire.com/products/coldfusion">Cold Fusion</OPTION>
        <OPTION VALUE="http://www.php.net">PHP</OPTION>
    </SELECT>
    <INPUT TYPE="radio" NAME="choice" CHECKED>View in Frame Below
    <INPUT TYPE="radio" NAME="choice">View in a new Window
</FORM>