<HTML>
<HEAD>
<TITLE>Binary Code - Sign Magnitude</TITLE>
<link rel="stylesheet" type="text/css" href="style.css" />

<STYLE>

.binary THEAD TD{
background-color: #E6D1E8;
color: #8C0099;
cursor: pointer;
cursor: hand;
border-radius: 10px;
text-align: center;
padding: 10px;
}


.binary TBODY TD{
background-color: #8C0099;
color: #FFFFFF;
cursor: pointer;
cursor: hand;
border-radius: 10px;
text-align: center;
padding: 16px;
font-size: 36pt;
}


.binary TBODY TD:hover{
background-color: #E6D1E8;
color: #8C0099;
}

#number{
width:500px;
margin-top: 6px;
background-color: #8C0099;
color: #FFFFFF;
border-radius: 10px;
text-align: center;
padding: 6px;
font-size: 36pt;
}

</STYLE>

<script>
var number=255;
 function clickBit(bit) {
	var bitCard =document.getElementById("bit" + bit); 	
	if (bitCard.innerHTML==1) {
		bitCard.innerHTML=0;
	} else {
		bitCard.innerHTML=1;
	}

	var st="";
	number=0;

	if (document.getElementById("bit64").innerHTML=="1") {
	    st += "64 + ";
		number+=64;
	}	
	if (document.getElementById("bit32").innerHTML=="1") {
	    st += "32 + ";
		number+=32;
	}	
	if (document.getElementById("bit16").innerHTML=="1") {
	    st += "16 + ";
		number+=16;
	}
	if (document.getElementById("bit8").innerHTML=="1") {
	    st += "8 + ";
		number+=8;
	}
	if (document.getElementById("bit4").innerHTML=="1") {
	    st += "4 + ";
		number+=4;		
	}
	if (document.getElementById("bit2").innerHTML=="1") {
	    st += "2 + ";
		number+=2;
	}
	if (document.getElementById("bit1").innerHTML=="1") {
	    st += "1 + ";
		number+=1;
	}
	if (document.getElementById("bit128").innerHTML=="1") {
	    st = "- ( " + st.substring(0,st.length-2) + " )  ";
		number=number*(-1);
	}	
	if (number!=0) { 
			document.getElementById("calculationArea").innerHTML = st.substring(0,st.length-2) + "<B><font color='#8C0099'> = " + number + "</font></B>";
	} else {
			document.getElementById("calculationArea").innerHTML = "<B><font color='#8C0099'>0</font></B>";
	}
	
	
}

var randomNumber = -127;
function getNumber() {
	randomNumber = Math.floor((Math.random()* 255))-127;
	document.getElementById("number").innerHTML=randomNumber;
}
var score = 0;
function checkAnswer() {
	if (number==randomNumber) {
		score++;
		document.getElementById("score").innerHTML=score;
		getNumber();
	} else {
		alert("Incorrect Answer! Try again!");
	}
		
}

function showHint() {
	if (document.getElementById("calculationArea").style.display=="none") {
		document.getElementById("calculationArea").style.display="block";
	} else {
		document.getElementById("calculationArea").style.display="none";
	}	
}
</script>
</HEAD>
<BODY onload="JavaScript: getNumber();">
<A href="http://www.101computing.net" target="_blank"><img src="101-computing-dot-net-s.png" border=0 width="160" height="63" style="position:fixed; bottom: 0px; right: 120px; z-index: -1;"></a>
<center>
<em>Click on the digits in the binary number below to change them.</em></br></br>
<center><big><b>Your Score: </b><span id="score">0</span><br><br>
<big><b>Denary Number: </b></big>
<div id="number">-127</div><br>
<big><b>Positive & Negative Binary Numbers using the Sign Magnitude Representation: </b></big><br/><br/>
<div style="width:520px; font-family: arial; font-size: 20px;" >
<TABLE class=binary style = "border-spacing: 6px;  border-collapse: separate;">
<thead>
<TR><TD valign=middle>+/-</TD><TD valign=middle>64</TD><TD valign=middle>32</TD><TD valign=middle>16</TD><TD valign=middle>8</TD><TD valign=middle>4</TD><TD valign=middle>2</TD><TD valign=middle>1</TD></TR>
</thead>
<tbody>
<TR><TD valign=middle onclick="Javascript: clickBit(128);" id="bit128">1</TD><TD valign=middle  onclick="Javascript: clickBit(64);" id="bit64">1</TD><TD valign=middle onclick="Javascript: clickBit(32);" id="bit32">1</TD><TD valign=middle onclick="Javascript: clickBit(16);" id="bit16">1</TD><TD valign=middle onclick="Javascript: clickBit(8);" id="bit8">1</TD><TD valign=middle onclick="Javascript: clickBit(4);" id="bit4">1</TD><TD valign=middle onclick="Javascript: clickBit(2);" id="bit2">1</TD><TD valign=middle onclick="Javascript: clickBit(1);" id="bit1">1</TD></TR>
</tbody>
</TD>
</TR>
</TABLE>
<br><br>
<a href="#" class="btn" onclick="JavaScript:checkAnswer();return true;">Check Answer</a>
<br><br><br>
<div id="calculationArea" style="display:none; padding:10px;border:2px solid #8C0099; text-align: center;-webkit-border-radius: 10px;-moz-border-radius: 10px;border-radius: 10px;-webkit-box-shadow: 4px 4px 3px 0px rgba(176,176,176,1);-moz-box-shadow: 4px 4px 3px 0px rgba(176,176,176,1);box-shadow: 4px 4px 3px 0px rgba(176,176,176,1);background-color: #E6D1E8;font-size: 18pt;padding: 20px 2px;">- ( 64 + 32 + 16 + 8 + 4 + 2 + 1 ) <B><font color='#8C0099'>= -127</font></B></div>
</div>
<a href="#" class="btn" onclick="JavaScript:showHint();return true;">Hint?</a>
<br><br><br>
</center>
</BODY>
</HTML>