<input type="text" name="pagego" size="4">
<input type="submit" name="go" value="GO"
onclick="window.location.href='frame.jsp?pagenum='+pagego.value">
<input type="submit" name="go" value="GO"
onclick="window.location.href='frame.jsp?pagenum='+pagego.value">
onclick="window.location.href='frame.jsp?what=${param.what}&pagenum='+pagego.value">