<FORM NAME="Calc">
    <TABLE BORDER=4><TR><TD>
     <INPUT TYPE="text"   NAME="Input" Size="16"><br>
    </TD></TR><TR><TD>
     <!-- all the buttons go here, just add as many as you like! -->

     <INPUT TYPE="button" NAME="one"   VALUE="  1  " OnClick="Calc.Input.value += '1'">

     <INPUT TYPE="button" NAME="two"   VALUE="  2  " OnCLick="Calc.Input.value += '2'">

     <INPUT TYPE="button" NAME="three" VALUE="  3  " OnClick="Calc.Input.value += '3'">

     <INPUT TYPE="button" NAME="plus"  VALUE="  +  " OnClick="Calc.Input.value += ' + '"><br>

     <INPUT TYPE="button" NAME="four"  VALUE="  4  " OnClick="Calc.Input.value += '4'">

     <INPUT TYPE="button" NAME="five"  VALUE="  5  " OnCLick="Calc.Input.value += '5'">

     <INPUT TYPE="button" NAME="six"   VALUE="  6  " OnClick="Calc.Input.value += '6'">

     <INPUT TYPE="button" NAME="minus" VALUE="  -   " OnClick="Calc.Input.value += ' - '"><br>

     <INPUT TYPE="button" NAME="seven" VALUE="  7  " OnClick="Calc.Input.value += '7'">

     <INPUT TYPE="button" NAME="eight" VALUE="  8  " OnCLick="Calc.Input.value += '8'">

     <INPUT TYPE="button" NAME="nine"  VALUE="  9  " OnClick="Calc.Input.value += '9'">

     <INPUT TYPE="button" NAME="times" VALUE="  x  " OnClick="Calc.Input.value += '  '"><br>

     <INPUT TYPE="button" NAME="clear" VALUE="  c  " OnClick="Calc.Input.value = ''">

     <INPUT TYPE="button" NAME="zero"  VALUE="  0  " OnClick="Calc.Input.value += '0'">

     <INPUT TYPE="button" NAME="DoIt"  VALUE="  =  " OnClick="Calc.Input.value = eval(Calc.Input.value)">
     <INPUT TYPE="button" NAME="div"   VALUE="  /   " OnClick="Calc.Input.value += ' / '"><br>
    </TD></TR>
    </TABLE>
    </FORM>