The first argument can be an empty string. I don't understand the second question. Instead of a submit button have a normal button with its onclick set to doFormPost():
Code:
function doFormPost()
{
var oNewWin = window.open("", "newTarget", "");
while(!oNewWin.document)
{
//Wait for window to open
}
document.forms[0].submit();
}
Your form would have the target attribute set to "newTarget".
--
Joe