Ya lo he consegido, he cambiado el codigo y funciona
`
function abre2(){
web = "pagina1.html";
window.open(web, 'frame1', '');
setTimeout ("abre3()", 1000)
}
function abre(){
web = "paginq2.html";
window.open(web, 'frame2', '');
setTimeout ("abre2()", 1000)
}
<td><a href="javascript
:abre()" onmouseout="MM_swapImgRestore()" onmouseover="MM_swapImage('Image1','','Imagenes/botonB.jpg',1)"><img src="Imagenes/botonA.jpg" name="Image1" alt="" height="45" width="100" border="0" /></a></td>