opeing and resist opening new tab with submit buttons

Revision 1
Hi I have got a form with two submit buttons. one button is to update the content in my select list and the other one to to send the form data.if the second button clicked i have to load the results in a new tab. but when i used base target it is opening new tab even if i put the condition like this inside my form

<base target="_self">


<base target="_Blank">