keys = new Array();
keys["f112"] = 'f1';
keys["f113"] = 'f2';
keys["f114"] = 'f3';
keys["f115"] = 'f4';
keys["f116"] = 'f5';
keys["f117"] = 'f6';
keys["f118"] = 'f7';
keys["f119"] = 'f8';
keys["f120"] = 'f9';
keys["f121"] = 'f10';
keys["f122"] = 'f11';
keys["f123"] = 'f12';
keys["f27"] = 'Escape';

document.onkeydown = function(){
//  F-key
if(window.event && keys["f"+window.event.keyCode]) {
window.event.keyCode = 505;
}
if(window.event && window.event.keyCode == 505) {
return false; // Debe devolver false
}
else
{
//Se eliminan los accesos rapidos, como Ctrl-N y Ctrl-B
if (window.event.ctrlKey)
{
//Ctrl-O
if(window.event.keyCode==79)
{
window.event.keyCode = 505;
self.location.href="InicioSesion.aspx";


}

// Saltar la comprobacion Ctrl-C/Ctrl-V/Ctrl-X
if((window.event.keyCode!=88)
&&(window.event.keyCode!=67)
&&(window.event.keyCode!=86))
{
//Matar el evento
window.event.cancelBubble = true; 
window.event.returnValue = false;
return false;
}
}
}
}