Insert this code into your HEAD of HTML

<!-- // == This Script Free To Use Providing This Notice Remains == // // == This Script Has Been In The http://www.DesignerWiz.com Javascript Public Archive Library == // // == NOTICE: Though This Material May Have Been In A Public Depository, Certain Author Copyright Restrictions May Apply == // --><script language="JavaScript" type="text/javascript"> <!-- Original: Christopher Nielsen (chris@bluegalaxy.net) --> <!-- Web Site: http://www.bluegalaxy.net --> <!-- This script and many more are available free online at --> <!-- The JavaScript Source!! http://javascript.internet.com --> <!-- Begin binary_numbers = new Array("0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"); function toBinary(High, Low) { var hiHex = "ABCDEF"; if (Low < 10 ) { LowNib = Low; } else { LowNib = 10 + hiHex.indexOf(Low); } if (High < 10 ) { HighNib = High; } else { HighNib = 10 + hiHex.indexOf(High); } eight_bits = binary_numbers[HighNib] + " " + binary_numbers[LowNib]; return eight_bits; } function Dec2Hex(Decimal) { var hexChars = "0123456789ABCDEF"; var a = Decimal % 16; var b = (Decimal - a)/16; hex = "" + hexChars.charAt(b) + hexChars.charAt(a); L = hexChars.charAt(a); H = hexChars.charAt(b); return hex; } var symbols = " !\"#$%&'()*+'-./0123456789:;<=>?@"; function toAscii () { var loAZ = "abcdefghijklmnopqrstuvwxyz"; symbols+= loAZ.toUpperCase(); symbols+= "[\\]^_`"; symbols+= loAZ; symbols+= "{|}~"; var loc; loc = symbols.indexOf(document.asciiform.Input.value); if (loc >-1) { Ascii_Decimal = 32 + loc; return (32 + loc); } return(0); // If not in range 32-126 return ZERO } function getAscii(some_value) { document.asciiform.toDec.value = toAscii(); document.asciiform.toHex.value = Dec2Hex(toAscii()); document.asciiform.binary.value = toBinary(H, L); } // End --> </script>

Insert this code into your BODY section

<center> <form name="asciiform" onsubmit="return false;"> <table border=1><tr><td> <center> Input one character: <input size=1 name=Input maxlength=1 onChange="getAscii(this.value)"> <p><input type=button value="display" onClick="document.asciiform.toDec.value=toAscii()"></center> <p><input size=10 name=toDec onFocus="this.blur()"> ASCII Decimal Output<br> <input size=10 name=toHex onFocus="this.blur()"> ASCII Hex Output<br> <input size=10 name=binary onFocus="this.blur()"> ASCII Binary Output </td></tr></table></form></center>

Simply Cut and Paste Script code
Be sure to properly place script position in HEAD & BODY sections of html 

This script has been in the Internet.com Public Library.