<form name="frm1">
<input type="text" name="firstValue" size="15" value=0>×
<input type="text" name="secondValue" size="15" value=0>=
<input type="text" name="result" size="15" value=0>
<br>
<INPUT type="button" name="buttoncalc" onClick="Calculate()" value="計算実行">
</form>