function preventSelection(element){  var
preventSelection = false;
  function addHandler(element, event, handler){

if (element.attachEvent)

element.attachEvent('on' + event, handler);

else

if (element.addEventListener)

element.addEventListener(event, handler, false);

}

function removeSelection(){

if (window.getSelection) { window.getSelection
().removeAllRanges(); }

else if (document.selection &&
document.selection.clear)

document.selection.clear();

//createPopup().show( 0, 0, 0, 0, 0 ); 
}

function killCtrlA(event){

var event = event || window.event;

var sender = event.target || event.srcElement;

if (sender.tagName.match(/INPUT|TEXTAREA/i))

return;

var key = event.keyCode || event.which;

if (event.ctrlKey && key == 'A'.charCodeAt(0))
  // 'A'.charCodeAt(0) можно заменить на 65

{

removeSelection();

if (event.preventDefault)

event.preventDefault();

else

event.returnValue = false;

}

}

// не даем выделять текст мышкой

addHandler(element, 'mousemove', function(){

if(preventSelection)

removeSelection();

//createPopup().show( 0, 0, 0, 0, 0 );        


});

addHandler(element, 'mousedown', function(event){

var event = event || window.event;

var sender = event.target || event.srcElement;

preventSelection = !sender.tagName.match
(/INPUT|TEXTAREA/i);

});

addHandler(element, 'mouseup', function(){

if (preventSelection)

removeSelection();

preventSelection = false;

});


addHandler(element, 'keydown', killCtrlA);

addHandler(element, 'keyup', killCtrlA);

}
preventSelection(document);