var allowRightClick = false;
document.onkeydown = OnKeyPress;
//document.onmousedown=click;

function OnKeyPress() {
	if (document.all) 
	{
		if (event.keyCode == 192) {
			allowRightClick = true;
		}

// ALT combination
if (event.altKey == true)
{
 switch(event.keyCode)
 {
  case 36: // ALT+HOME
    event.keyCode=0; 
    event.returnValue=false;
    event.cancelBuble=true;
    alert('Please click the Home button.');
    break;


  case 37: // ALT+LEFT ARROW
  case 39: // ALT+RIGHT ARROW
    event.returnValue=false;
    break;
 }
}

// CTRL combination    
if (event.ctrlKey == true)
{
 switch(event.keyCode)
 {
  case 66: // CTRL+B
  case 68: // CTRL+D
  case 69: // CTRL+E
  case 70: // CTRL+F
  case 72: // CTRL+H    
  case 73: // CTRL+I
  case 82: // CTRL+R
  case 76: // CTRL+L
  case 78: // CTRL+N  
  case 79: // CTRL+O  
  case 80: // CTRL+P
  case 87: // CTRL+W  
    event.keyCode=0;  
    event.returnValue=false;
    event.cancelBuble=true;
    break;
 }
}

// SHIFT combination    
if (event.shiftKey == true)
{
 switch(event.keyCode)
 {
  case 121: // SHIFT+F10
    event.returnValue=false;
    break;
 }
}

// Single keys
switch(event.keyCode)
{
 case 116: // F5
 case 122: // F11
    event.keyCode=0;  
    event.returnValue=false;
    break;
}

// TAB key
if((event.keyCode==8 && event.srcElement.type!="text"))
{
 event.keyCode=0;  
 event.returnValue=false;
}

// ENTER key
if(event.srcElement.type=="text" || event.srcElement.type=="checkbox" || event.srcElement.type=="radio")
{
 if(event.keyCode==13)
 {
  event.keyCode=0;  
  event.returnValue=false;
 }
}

	}
}

function onRightClick()
{
	return allowRightClick;
}