function btnThingy(){
   document.calculator.result.value +="±";}

function btnLeftBrac(){
   document.calculator.result.value +="(";}

function btnRightBrac(){
   document.calculator.result.value +=")";}

function btnMinus(){
   document.calculator.result.value +="-";}

function btn7(){
   document.calculator.result.value +="7";}

function btn8(){
   document.calculator.result.value +="8";}

function btn9(){
   document.calculator.result.value +="9";}

function btn4(){
   document.calculator.result.value +="4";}

function btn5(){
   document.calculator.result.value +="5";}

function btn6(){
   document.calculator.result.value +="6";}

function btn1(){
   document.calculator.result.value +="1";}

function btn2(){
   document.calculator.result.value +="2";}

function btn3(){
    document.calculator.result.value +="3";}

function btnPlus(){
 document.calculator.result.value +="+";}

function btn0(){
   document.calculator.result.value +="0";}

// method to evalute the given values with the cal display
// returns the result to the display
function equal(){
   var res = eval(document.calculator.result.value);
   document.calculator.result.value = res;
}

function clr(){
   document.calculator.result.value = " ";
}