function SHA1 (msg) {
	 
		function rotate_left(n,s) {
			var t4 = ( n<<s ) | (n>>>(32-s));
			return t4;
		};
	 
		function lsb_hex(val) {
			var str="";
			var i;
			var vh;
			var vl;
	 
			for( i=0; i<=6; i+=2 ) {
				vh = (val>>>(i*4+4))&0x0f;
				vl = (val>>>(i*4))&0x0f;
				str += vh.toString(16) + vl.toString(16);
			}
			return str;
		};
	 
		function cvt_hex(val) {
			var str="";
			var i;
			var v;
	 
			for( i=7; i>=0; i-- ) {
				v = (val>>>(i*4))&0x0f;
				str += v.toString(16);
			}
			return str;
		};
	 
	 
		function Utf8Encode(string) {
			string = string.replace(/\r\n/g,"\n");
			var utftext = "";
	 
			for (var n = 0; n < string.length; n++) {
	 
				var c = string.charCodeAt(n);
	 
				if (c < 128) {
					utftext += String.fromCharCode(c);
				}
				else if((c > 127) && (c < 2048)) {
					utftext += String.fromCharCode((c >> 6) | 192);
					utftext += String.fromCharCode((c & 63) | 128);
				}
				else {
					utftext += String.fromCharCode((c >> 12) | 224);
					utftext += String.fromCharCode(((c >> 6) & 63) | 128);
					utftext += String.fromCharCode((c & 63) | 128);
				}
	 
			}
	 
			return utftext;
		};
	 
		var blockstart;
		var i, j;
		var W = new Array(80);
		var H0 = 0x67452301;
		var H1 = 0xEFCDAB89;
		var H2 = 0x98BADCFE;
		var H3 = 0x10325476;
		var H4 = 0xC3D2E1F0;
		var A, B, C, D, E;
		var temp;
	 
		msg = Utf8Encode(msg);
	 
		var msg_len = msg.length;
	 
		var word_array = new Array();
		for( i=0; i<msg_len-3; i+=4 ) {
			j = msg.charCodeAt(i)<<24 | msg.charCodeAt(i+1)<<16 |
			msg.charCodeAt(i+2)<<8 | msg.charCodeAt(i+3);
			word_array.push( j );
		}
	 
		switch( msg_len % 4 ) {
			case 0:
				i = 0x080000000;
			break;
			case 1:
				i = msg.charCodeAt(msg_len-1)<<24 | 0x0800000;
			break;
	 
			case 2:
				i = msg.charCodeAt(msg_len-2)<<24 | msg.charCodeAt(msg_len-1)<<16 | 0x08000;
			break;
	 
			case 3:
				i = msg.charCodeAt(msg_len-3)<<24 | msg.charCodeAt(msg_len-2)<<16 | msg.charCodeAt(msg_len-1)<<8	| 0x80;
			break;
		}
	 
		word_array.push( i );
	 
		while( (word_array.length % 16) != 14 ) word_array.push( 0 );
	 
		word_array.push( msg_len>>>29 );
		word_array.push( (msg_len<<3)&0x0ffffffff );
	 
	 
		for ( blockstart=0; blockstart<word_array.length; blockstart+=16 ) {
	 
			for( i=0; i<16; i++ ) W[i] = word_array[blockstart+i];
			for( i=16; i<=79; i++ ) W[i] = rotate_left(W[i-3] ^ W[i-8] ^ W[i-14] ^ W[i-16], 1);
	 
			A = H0;
			B = H1;
			C = H2;
			D = H3;
			E = H4;
	 
			for( i= 0; i<=19; i++ ) {
				temp = (rotate_left(A,5) + ((B&C) | (~B&D)) + E + W[i] + 0x5A827999) & 0x0ffffffff;
				E = D;
				D = C;
				C = rotate_left(B,30);
				B = A;
				A = temp;
			}
	 
			for( i=20; i<=39; i++ ) {
				temp = (rotate_left(A,5) + (B ^ C ^ D) + E + W[i] + 0x6ED9EBA1) & 0x0ffffffff;
				E = D;
				D = C;
				C = rotate_left(B,30);
				B = A;
				A = temp;
			}
	 
			for( i=40; i<=59; i++ ) {
				temp = (rotate_left(A,5) + ((B&C) | (B&D) | (C&D)) + E + W[i] + 0x8F1BBCDC) & 0x0ffffffff;
				E = D;
				D = C;
				C = rotate_left(B,30);
				B = A;
				A = temp;
			}
	 
			for( i=60; i<=79; i++ ) {
				temp = (rotate_left(A,5) + (B ^ C ^ D) + E + W[i] + 0xCA62C1D6) & 0x0ffffffff;
				E = D;
				D = C;
				C = rotate_left(B,30);
				B = A;
				A = temp;
			}
	 
			H0 = (H0 + A) & 0x0ffffffff;
			H1 = (H1 + B) & 0x0ffffffff;
			H2 = (H2 + C) & 0x0ffffffff;
			H3 = (H3 + D) & 0x0ffffffff;
			H4 = (H4 + E) & 0x0ffffffff;
	 
		}
	 
		var temp = cvt_hex(H0) + cvt_hex(H1) + cvt_hex(H2) + cvt_hex(H3) + cvt_hex(H4);
	 
		return temp.toLowerCase();
	 
	}