javascript - Getting tax price to calculate before submitting a form -
    i'm trying tax value in checkout page calculate once state field selected. want without having submit form want display tax rate on page before order processed.   i sure have ajax , have used ajax limited amount of times. know send request ajax php page , ajax pulls field need. need pull is, if ohio selected need pull value of 1.065. if other state pulled need value of 1.   i have state variables listed in array format because using options state dropdown..   $taxvalue['ohio'] = "ohio"; $taxvalue['virginia'] = "virginia";   etc   then tried if isset statement when ohio selected pull $taxed_state value of 1.065. else else untaxed_state.   $taxed_state = 1.065; $untaxed_state = 1;      if(isset($taxvalue['ohio'])){             $taxed_state;        } else {          $untaxed_state;     }   this how trying configure tax rate know work once can state set before form submitted.       $base_price = 0;             foreach($_session['shopp...