Need Basic Javascript Help

timithyy · Sep 10, 2015

Hi guys I'm just a beginner at javascript/html. I'm trying to finish off this calculator and am having troubles adding the division and multiply signs in (and making them functional), if someone could show me how to do that it would be much appreciated

Code:

<!DOCTYPE html>
<CENTER>
 <FORM name="Keypad" action="">
  <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>
         <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="">
     </TD>
     <TD align=middle><input name="btnDivide" type="Button" value="       " onclick="">
     </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 Accumulate = 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 )
                   Accumulate += parseFloat(Readout);
                else if ( '-' == PendingOp )
                        Accumulate -= parseFloat(Readout);
                else
                    Accumulate = parseFloat(Readout);
                 FKeyPad.ReadOut.value = Accumulate;
                 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 () {
            Accumulate = 0;
            PendingOp = "";
            ClearEntry();
      }

	  
	  function Neg () {
            FKeyPad.ReadOut.value = "###";
      }

	  
	  function Percent () {
           FKeyPad.ReadOut.value = (parseFloat(FKeyPad.ReadOut.value) / 100) * parseFloat(Accumulate);
}
// End -->
</SCRIPT>