Kalkulator dengan java script

Mari kita bahas tentang "java script".
Disini saya akan menjelaskan sedikit tentang pembuatan kalkulator dengan menggunakan java script yang nantinya akan bisa ditampilkan dalam web (berbasis web). Berikut ini contoh tampilan kalkulator tersebut dan asih bisa dirubah sesuai dengan keinginan desain anda:



Dan disini untuk scriptnya:

<CENTER>
<FORM name="Keypad" action="">

<!-- Original: http://www.dummyproof.com/javascripts -->

<! >
<! >

<TABLE>
<B>

<TABLE border=2 width=50 height=60 cellpadding=1 cellspacing=5>
<TR>
<TD colspan=3 align=middle>
<input name="ReadOut" type="Text" size=24 value="0"
width=100%>
</TD>
<TD
</TD>
<TD>
<input name="btnClear" type="Button" value=" C "
onclick="Clear()">
</TD>
<TD><input name="btnClearEntry" type="Button" value="
CE " onclick="ClearEntry()">
</TD>
</TR>
<TR>
<TD>
<input name="btnSeven" type="Button" value=" 7 "
onclick="NumPressed(7)">
</TD>
<TD>
<input name="btnEight" type="Button" value=" 8 "
onclick="NumPressed(8)">
</TD>
<TD>
<input name="btnNine" type="Button" value=" 9 "
onclick="NumPressed(9)">
</TD>
<TD>
</TD>
<TD>
<input name="btnNeg" type="Button" value=" +/- "
onclick="Neg()">
</TD>
<TD>
<input name="btnPercent" type="Button" value=" %
" onclick="Percent()">
</TD>
</TR>
<TR>
<TD>
<input name="btnFour" type="Button" value=" 4 "
onclick="NumPressed(4)">
</TD>
<TD>
<input name="btnFive" type="Button" value=" 5 "
onclick="NumPressed(5)">
</TD>
<TD>
<input name="btnSix" type="Button" value=" 6 "
onclick="NumPressed(6)">
</TD>
<TD>
</TD>
<TD align=middle><input name="btnPlus" type="Button"
value=" + " onclick="Operation('+')">
</TD>
<TD align=middle><input name="btnMinus" type="Button"
value=" - " onclick="Operation('-')">
</TD>
</TR>
<TR>
<TD>
<input name="btnOne" type="Button" value=" 1 "
onclick="NumPressed(1)">
</TD>
<TD>
<input name="btnTwo" type="Button" value=" 2 "
onclick="NumPressed(2)">
</TD>
<TD>
<input name="btnThree" type="Button" value=" 3 "
onclick="NumPressed(3)">
</TD>
<TD>
</TD>
<TD align=middle><input name="btnMultiply" type="Button"
value=" * " onclick="Operation('*')">
</TD>
<TD align=middle><input name="btnDivide" type="Button"
value=" / " onclick="Operation('/')">
</TD>
</TR>
<TR>
<TD>
<input name="btnZero" type="Button" value=" 0 "
onclick="NumPressed(0)">
</TD>
<TD>
<input name="btnDecimal" type="Button" value=" .
" onclick="Decimal()">
</TD>
<TD colspan=3>
</TD>
<TD>
<input name="btnEquals" type="Button" value=" =
" onclick="Operation('=')">
</TD>
</TR>
</TABLE>
</TABLE>
</B>
</FORM>
</CENTER>
<font face="Verdana, Arial, Helvetica" size=2>
<SCRIPT LANGUAGE="JavaScript">
<!-- Begin
var FKeyPad = document.Keypad;
var Accum = 0;
var FlagNewNum = false;
var PendingOp = "";
function NumPressed (Num) {
if (FlagNewNum) {
FKeyPad.ReadOut.value = Num;
FlagNewNum = false;
}
else {
if (FKeyPad.ReadOut.value == "0")
FKeyPad.ReadOut.value = Num;
else
FKeyPad.ReadOut.value += Num;
}
}
function Operation (Op) {
var Readout = FKeyPad.ReadOut.value;
if (FlagNewNum && PendingOp != "=");
else
{
FlagNewNum = true;
if ( '+' == PendingOp )
Accum += parseFloat(Readout);
else if ( '-' == PendingOp )
Accum -= parseFloat(Readout);
else if ( '/' == PendingOp )
Accum /= parseFloat(Readout);
else if ( '*' == PendingOp )
Accum *= parseFloat(Readout);
else
Accum = parseFloat(Readout);
FKeyPad.ReadOut.value = Accum;
PendingOp = Op;
}
}
function Decimal () {
var curReadOut = FKeyPad.ReadOut.value;
if (FlagNewNum) {
curReadOut = "0.";
FlagNewNum = false;
}
else
{

if (curReadOut.indexOf(".") == -1)
curReadOut += ".";
}

FKeyPad.ReadOut.value = curReadOut;
}
function ClearEntry () {
FKeyPad.ReadOut.value = "0";
FlagNewNum = true;
}
function Clear () {
Accum = 0;
PendingOp = "";
ClearEntry();
}
function Neg () {
FKeyPad.ReadOut.value = parseFloat(FKeyPad.ReadOut.value) * -1;
}
function Percent () {
FKeyPad.ReadOut.value = (parseFloat(FKeyPad.ReadOut.value) / 100) * parseFloat(Accum);
}
// End -->
</SCRIPT>