I've been using an adapted version of this code:
I've adapted it to have one button to search multiple sites..
<script>
function multiSearch(){
window.open (SEARCH URL A);
window.open (SEARCH URL B);
window.open (SEARCH URL B);
</script>
<input type="button" value="Latest Results" onClick="multiSearch;">
Which works fine but in Chrome only first Search window opens as a new tab, the other two open as pop ups. Is there anyway to get them all to open as tabs?
window.open(url, '_blank')
sometimes opens in a new tab, but usually in a new window depending on how it is used. You cannot control it directly using Javascript unfortunately.