function menuover(obj){
	obj.style.background='url(http://www.rock-music-hall.nl/res/images/layout/menuitemselected.jpg) top left no-repeat';
}

function menuout(obj){
	obj.style.background='';
}

function login(salt_password) {	
	document.getElementById('password').value = sha1hash(salt_password + ':' + sha1hash(document.getElementById('username').value.toLowerCase() + ':' + document.getElementById('password_temp').value));
	document.getElementById('password_temp').value = '';
	return true;
}

function sha1hash(msg) {

    var K = [0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xca62c1d6];

    msg += String.fromCharCode(0x80);

    var l = Math.ceil(msg.length/4) + 2; 
    var N = Math.ceil(l/16);              
    var M = new Array(N);
    for (var i=0; i<N; i++) {
        M[i] = new Array(16);
        for (var j=0; j<16; j++) {
            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));
        }
    }

    M[N-1][14] = ((msg.length-1)*8) / Math.pow(2, 32); M[N-1][14] = Math.floor(M[N-1][14])
    M[N-1][15] = ((msg.length-1)*8) & 0xffffffff;

    var H0 = 0x67452301;
    var H1 = 0xefcdab89;
    var H2 = 0x98badcfe;
    var H3 = 0x10325476;
    var H4 = 0xc3d2e1f0;

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

        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);

        a = H0; b = H1; c = H2; d = H3; e = H4;

        for (var t=0; t<80; t++) {
            var s = Math.floor(t/20);
            var 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;
        }


        H0 = (H0+a) & 0xffffffff; 
        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(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;                    
    }
}

function ROTL(x, n)
{
    return (x<<n) | (x>>>(32-n));
}

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 inserttags(tagOpen, tagClose, sampleText) {
	var txtarea;
	if (document.editform) {
		txtarea = document.editform.box;
	} else {
		var areas = document.getElementsByTagName('textarea');
		txtarea = areas[0];
	}
	var selText, isSample = false;

	if (document.selection  && document.selection.createRange) {

		if (document.documentElement && document.documentElement.scrollTop)
			var winScroll = document.documentElement.scrollTop
		else if (document.body)
			var winScroll = document.body.scrollTop;
		txtarea.focus();
		var range = document.selection.createRange();
		selText = range.text;
		checkSelectedText();
		range.text = tagOpen + selText + tagClose;
		if (isSample && range.moveStart) {
			if (window.opera)
				tagClose = tagClose.replace(/\n/g,'');
			range.moveStart('character', - tagClose.length - selText.length); 
			range.moveEnd('character', - tagClose.length); 
		}
		range.select();   
		if (document.documentElement && document.documentElement.scrollTop)
			document.documentElement.scrollTop = winScroll
		else if (document.body)
			document.body.scrollTop = winScroll;

	} else if (txtarea.selectionStart || txtarea.selectionStart == '0') {

		var textScroll = txtarea.scrollTop;
		txtarea.focus();
		
		var startPos = txtarea.selectionStart;
		var endPos = txtarea.selectionEnd;
		selText = txtarea.value.substring(startPos, endPos);
		
		checkSelectedText();
		txtarea.value = txtarea.value.substring(0, startPos)
			+ tagOpen + selText + tagClose
			+ txtarea.value.substring(endPos, txtarea.value.length);
		
		if (isSample) {
			txtarea.selectionStart = startPos + tagOpen.length;
			txtarea.selectionEnd = startPos + tagOpen.length + selText.length;
		} else {
			txtarea.selectionStart = startPos + tagOpen.length + selText.length + tagClose.length;
			txtarea.selectionEnd = txtarea.selectionStart;
		}
		
		txtarea.scrollTop = textScroll;
	} 

	function checkSelectedText(){
		if (!selText) {
			selText = sampleText;
			isSample = true;
		} else if (selText.charAt(selText.length - 1) == ' ') {
			selText = selText.substring(0, selText.length - 1);
			tagClose += ' '
		} 
	}

}