Do you mean that the result (the number after "Number1:") can be less than
10.
If so, change the function to convert the result to add a leading zero.
function calcform()
{
with (document.form1)
{ number1.value = +number1.value + +number2.value;
if (number1.value < 10)
number1.value = '0' + number1.value;
}
/* Note the extra + operators. */
}
But if it gets greater than 100, you will need two leading zeroes when < 10
and one leading zero when between 10 and 99 inclusive
function calcform()
{
with (document.form1)
{ number1.value = +number1.value + +number2.value;
if (number1.value < 10)
number1.value = '00' + number1.value;
else if (number1.value < 100)
number1.value = '0' + number1.value;
}
/* Note the extra + operators. */
}