function myFunction3() {
   var myString3="";
   if (confirm) 
      document.myForm3.myText1.value = eval(document.myForm3.myText1.value);
   else 
      document.myForm3.myText1.value = myString3;
}

function coren() {
   var myString3="";
   if (confirm) 
      document.myForm3.myText1.value = eval(document.myForm3.myText1.value / document.myForm3.myText1.value);
   else 
      document.myForm3.myText1.value = myString3;
}

function addchar(character, field) {
  field.value = field.value + character;
}
function delchar(field) {
  if (field.value.length != 0) {
    field.value = field.value.substring(0, field.value.length - 1);
  }
}
function clearfield(field) {
  field.value = '';
}