var keyStr = 	"ABCDEFGHIJKLMNOPQRSTUVWXYZ" + //all caps
				"abcdefghijklmnopqrstuvwxyz" + //all lowercase
				"0123456789+/="; // all numbers plus +/=

//Here's the encode function
function encode64(inp) {
	var out = ""; //This is the output
	var chr1, chr2, chr3 = ""; //These are the 3 bytes to be encoded
	var enc1, enc2, enc3, enc4 = ""; //These are the 4 encoded bytes
	var i = 0; //Position counter
	
	do { //Set up the loop here
		chr1 = inp.charCodeAt(i++); //Grab the first byte
		chr2 = inp.charCodeAt(i++); //Grab the second byte
		chr3 = inp.charCodeAt(i++); //Grab the third byte
		
		//Here is the actual base64 encode part.
		//There really is only one way to do it.
		enc1 = chr1 >> 2;
		enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
		enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
		enc4 = chr3 & 63;

		if (isNaN(chr2))
			enc3 = enc4 = 64;
		else if (isNaN(chr3))
			enc4 = 64;

		//Lets spit out the 4 encoded bytes
		out = out + keyStr.charAt(enc1) + keyStr.charAt(enc2) + keyStr.charAt(enc3) + keyStr.charAt(enc4);

		// OK, now clean out the variables used.
		chr1 = chr2 = chr3 = "";
		enc1 = enc2 = enc3 = enc4 = "";

	} while (i < inp.length); //And finish off the loop

	//Now return the encoded values.
	return out;
}

//Here's the decode function
function decode64(inp) {
	var out = ""; //This is the output
	var chr1, chr2, chr3 = ""; //These are the 3 decoded bytes
	var enc1, enc2, enc3, enc4 = ""; //These are the 4 bytes to be decoded
	var i = 0; //Position counter

	// remove all characters that are not A-Z, a-z, 0-9, +, /, or =
	var base64test = /[^A-Za-z0-9+\/=]/g;
	
	if (base64test.exec(inp)) { //Do some error checking
		alert(	"There were invalid base64 characters in the input text.n" +
				"Valid base64 characters are A-Z, a-z, 0-9, ?+?, ?/?, and ?=?\n" +
				"Expect errors in decoding.");
	}
	inp = inp.replace(/[^A-Za-z0-9+\/=]/g, "");

	do { //Here's the decode loop.
		//Grab 4 bytes of encoded content.
		enc1 = keyStr.indexOf(inp.charAt(i++));
		enc2 = keyStr.indexOf(inp.charAt(i++));
		enc3 = keyStr.indexOf(inp.charAt(i++));
		enc4 = keyStr.indexOf(inp.charAt(i++));
		
		//Heres the decode part. There's really only one way to do it.
		chr1 = (enc1 << 2) | (enc2 >> 4);
		chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
		chr3 = ((enc3 & 3) << 6) | enc4;
		
		//Start to output decoded content
		out = out + String.fromCharCode(chr1);
		
		if (enc3 != 64)
			out = out + String.fromCharCode(chr2);
		if (enc4 != 64)
			out = out + String.fromCharCode(chr3);
		
		//now clean out the variables used
		chr1 = chr2 = chr3 = "";
		enc1 = enc2 = enc3 = enc4 = "";
	} while (i < inp.length); //finish off the loop
	
	//Now return the decoded values.
	return out;
}

/* USAGE:
<form name="Base64">

Enter what you want encoded or decoded and push the Encode or Decode buttons<br>

<textarea name="Test" cols="40" rows="6"></textarea><br>

<input type="button" name="encode" value="Encode" onClick="javascript:document.Base64.Test.value=encode64(document.Base64.Test.value);">
<input type="button" name="decode" value="Decode" onClick="javascript:document.Base64.Test.value=decode64(document.Base64.Test.value);">

</form>
*/