from the TOP of your page, BEFORE ANY HTML CODING AT ALL (ie, before the <html> tag or any other output / print statements):
if($HTTP_POST_VARS['submission_name']){
header("Location: HTTP_DOMAIN_NAME_OR_ABSOLUTE_URL/?var1=".$HTTP_POST_VARS['var1']."&var2=".$HTTP_POST_VARS['var2']."&var3=".$HTTP_POST_VARS['var3']."#you_can_set_a_target_too!");
exit;
}
Then, in your HTML:
<INPUT TYPE="text" SIZE="50" NAME="var1">
<INPUT TYPE="text" SIZE="50" NAME="var2">
<INPUT TYPE="text" SIZE="50" NAME="var3">
<INPUT TYPE="submit" NAME="submission_name" VALUE="Button Displayed Name">
Keep in mind, you can change these:
"submission_name", to identify your button's specific action from any other buttons you have.
"Button Display Name", for obvious reasons.
And all of the input for your form. As long as you keep the names of input values matched with those names in the header link at the top.