Velocity Reviews - Need assistance with <form> & <input>

Sup, i'm new to this forum. I was wondering how one would go about sending whatever the user types in text box; to the end of the <form action=. If one does not have access to the websites code source, how would one go about this?

Code:

<!DOCTYPE html> <html> <head> <style type="text/css"> a:link {color:#687BC6;} /* unvisited link */ a:visited {color:#00FF00;} /* visited link */ a:hover {color:#000;} /* mouse over link */ a:active {color:#00EE;} /* selected link */ </style> </head> <body> <form name="form1" method="get" action="http://www.blah.com/right-now/" target="_blank"> <table border="0" cellpadding="2" cellspacing="0"> <tr><td>ZC:</td> <td><input name="fld-zip" type="text" maxlength="7" size="15"></td></tr> <tr><td> </td> <td><input type="submit" name=Submit value="Submit this"></td></tr> </table> </form> </body> </html>

Pretty much asking how you can add ***what you put in text box*** to the end of URL ***/???*** when you click the submit button.
Can someone please give me some feedback?Or atleast guide me in the right direction? / right language?