/**
 * Gets the value of the specified cookie.
 *
 * name  Name of the desired cookie.
 *
 * Returns a string containing value of specified cookie,
 *   or null if cookie does not exist.
 */
 function getCookie(name) {
    var dc = document.cookie;
    var prefix = name + "=";
    var begin = dc.indexOf("; " + prefix);
    if (begin == -1) {
        begin = dc.indexOf(prefix);
       if (begin != 0) return null;
    } else {
        begin += 2;
    }
    var end = document.cookie.indexOf(";", begin);
    if (end == -1) {
        end = dc.length;
    }
    return unescape(dc.substring(begin + prefix.length, end));
}

function deleteCookie(name, path, domain) {
  if (getCookie(name)) {
      document.cookie = name + "=" + ((path) ? "; path=" + path : "") +
      ((domain) ? "; domain=" + domain : "") +
      "; expires=Thu, 01-Jan-70 00:00:01 GMT";
  }
}

//------------------------------------------------------------------------------
//      See below for the source code of the JavaScript implementation. You are welcome to re-use these scripts [without any warranty express or implied] provided you retain my copyright notice and when possible a link to my website. If you have any queries or find any problems, please contact me.
//(C) 2002-2005 Chris Veness

function sha1Hash(msg)
{
    // constants [4.2.1]
    var K = new Array(0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xca62c1d6);

    // PREPROCESSING 

    msg += String.fromCharCode(0x80); // add trailing '1' bit to string [5.1.1]

    // convert string msg into 512-bit/16-integer blocks arrays of ints [5.2.1]
    var l = Math.ceil(msg.length/4) + 2;  // long enough to contain msg plus 
                                          // 2-word length
    var N = Math.ceil(l/16);              // in N 16-int blocks
    var M = new Array(N);
    for (var i=0; i<N; i++) {
        M[i] = new Array(16);
        for (var j=0; j<16; j++) {  // encode 4 chars per integer, big-endian 
                                    //encoding
            M[i][j] = (msg.charCodeAt(i*64+j*4)<<24) | 
            (msg.charCodeAt(i*64+j*4+1)<<16) | 
            (msg.charCodeAt(i*64+j*4+2)<<8) | (msg.charCodeAt(i*64+j*4+3));
        }
    }
    // add length (in bits) into final pair of 32-bit integers (big-endian) 
    //[5.1.1]
    M[N-1][14] = ((msg.length-1) >>> 30) * 8;
    M[N-1][15] = ((msg.length-1)*8) & 0xffffffff;

    // set initial hash value [5.3.1]
    var H0 = 0x67452301;
    var H1 = 0xefcdab89;
    var H2 = 0x98badcfe;
    var H3 = 0x10325476;
    var H4 = 0xc3d2e1f0;

    // HASH COMPUTATION [6.1.2]

    var W = new Array(80); var a, b, c, d, e;
    for (var i=0; i<N; i++) {

        // 1 - prepare message schedule 'W'
        for (var t=0;  t<16; t++) W[t] = M[i][t];
            for (var t=16; t<80; t++) W[t] = ROTL(W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16], 1);

                // 2 - initialise five working variables a, b, c, d, e with 
                //previous hash value
                a = H0; b = H1; c = H2; d = H3; e = H4;

                // 3 - main loop
                for (var t=0; t<80; t++) {
                    var s = Math.floor(t/20); // seq for blocks of 'f' 
                                              //functions and 'K' constants
                    T = (ROTL(a,5) + f(s,b,c,d) + e + K[s] + W[t]) & 0xffffffff;
                    e = d;
                    d = c;
                    c = ROTL(b, 30);
                    b = a;
                    a = T;
                }

            // 4 - compute the new intermediate hash value
            H0 = (H0+a) & 0xffffffff;  // note 'addition modulo 2^32'
            H1 = (H1+b) & 0xffffffff; 
            H2 = (H2+c) & 0xffffffff; 
            H3 = (H3+d) & 0xffffffff; 
            H4 = (H4+e) & 0xffffffff;
        }

        return H0.toHexStr() + H1.toHexStr() + H2.toHexStr() + H3.toHexStr() + H4.toHexStr();
    }

    //
    // function 'f' [4.1.1]
    //
    function f(s, x, y, z) 
    {
        switch (s) {
            case 0: return (x & y) ^ (~x & z);
            case 1: return x ^ y ^ z;
            case 2: return (x & y) ^ (x & z) ^ (y & z);
            case 3: return x ^ y ^ z;
        }
    }

    //
    // rotate left (circular left shift) value x by n positions [3.2.5]
    //
    function ROTL(x, n)
    {
        return (x<<n) | (x>>>(32-n));
    }

    //
    // extend Number class with a tailored hex-string method 
    //   (note toString(16) is implementation-dependant, and 
    //   in IE returns signed numbers when used on full words)
    //
    Number.prototype.toHexStr = function()
    {
        var s="", v;
        for (var i=7; i>=0; i--) { v = (this>>>(i*4)) & 0xf; s += v.toString(16); }
        return s;
    }

function loginCheck() {
    if (document.personLog.haslogin.checked == true) {
        document.personLog.loginName.disabled = false;
        document.personLog.pass1.disabled = false;
        document.personLog.pass2.disabled = false;
        document.personLog.update.disabled = false;
    } else {
        document.personLog.loginName.disabled = true;
        document.personLog.pass1.disabled = true;
        document.personLog.pass2.disabled = true;
        document.personLog.update.disabled = false;
    }
}