function tag(elem,name) {
    // If the context element is not provided, search the whole document
    return (elem || document).getElementsByTagName(name);
} 

function id(name) {
    return document.getElementById(name);

} 

// Remove a single Node from the DOM
function remove( elem ) {
    if ( elem ) elem.parentNode.removeChild( elem );
} 



// Remove all of an ElementÔÇÖs children from the DOM
function empty( elem ) {
    while ( elem.firstChild )
        remove( elem.firstChild );
} 


function create( elem ) {
    return document.createElementNS ?
        document.createElementNS( 'http://www.w3.org/1999/xhtml', elem ) :
        document.createElement( elem );
} 


function last( elem ) {
    elem = elem.lastChild;
    return elem && elem.nodeType != 1 ?
        prevSibling( elem ) : elem;
} 

function checkElem(a) {
    var r = [];
    // Force the argument into an array, if it isnÔÇÖt already
    if ( a.constructor != Array ) a = [ a ];

    for ( var i = 0; i < a.length; i++ ) {
        // If thereÔÇÖs a String
        if ( a[i].constructor == String ) {
            // Create a temporary element to house the HTML
            var div = document.createElement("div");

            // Inject the HTML, to convert it into a DOM structure
            div.innerHTML = a[i];

             // Extract the DOM structure back out of the temp DIV
             for ( var j = 0; j < div.childNodes.length; j++ )
                 r[r.length] = div.childNodes[j];
        } else if ( a[i].length ) { // If itÔÇÖs an array
            // Assume that itÔÇÖs an array of DOM Nodes
            for ( var j = 0; j < a[i].length; j++ )
                r[r.length] = a[i][j];
        } else { // Otherwise, assume itÔÇÖs a DOM Node
            r[r.length] = a[i];
        }
    }
    return r;
} 

function before( parent, before, elem ) {
    // Check to see if no parent node was provided
    if ( elem == null ) {
        elem = before;
        before = parent;
        parent  = before.parentNode;
    }

    // Get the new array of elements
    var elems = checkElem( elem );

    // Move through the array backwards,
    // because weÔÇÖre prepending elements
    for ( var i = elems.length - 1; i >= 0; i-- ) {
        parent.insertBefore( elems[i], before );
    }
}

function append( parent, elem ) {
    // Get the array of elements
    var elems = checkElem( elem );

    // Append them all to the element
    for ( var i = 0; i <= elems.length; i++ ) {
        parent.appendChild( elems[i] );
    }
} 


// Find the horizontal position of the cursor
function getX(e) {
    // Normalize the event object
    e = e || window.event;

    // Check for the non-IE position, then the IE position, and finally return 0
    return e.pageX || e.clientX + document.body.scrollLeft || 0;
}

// Find the vertical position of the cursor
function getY(e) {
    // Normalize the event object
    e = e || window.event;

    // Check for the non-IE position, then the IE position, and finally return 0
	// aktualni pozice kliknuti vzhledem viditelnemu screenu e.clientY
    return e.pageY || document.body.scrollTop + document.documentElement.scrollTop || 0;
}
 

//http://www.howtocreate.co.uk/tutorials/javascript/browserwindow
function getScrollXY() {
  var scrOfX = 0, scrOfY = 0;
  if( typeof( window.pageYOffset ) == 'number' ) {
    //Netscape compliant
    scrOfY = window.pageYOffset;
    scrOfX = window.pageXOffset;
  } else if( document.body && ( document.body.scrollLeft || document.body.scrollTop ) ) {
    //DOM compliant
    scrOfY = document.body.scrollTop;
    scrOfX = document.body.scrollLeft;
  } else if( document.documentElement && ( document.documentElement.scrollLeft || document.documentElement.scrollTop ) ) {
    //IE6 standards compliant mode
    scrOfY = document.documentElement.scrollTop;
    scrOfX = document.documentElement.scrollLeft;
  }
  return [ scrOfX, scrOfY ];
}