I see some similar questions here (like JavaScript: Check if CTRL button was pressed) but my problem is actually the event triggering. My js code:
// Lis
Your event has a property named ctrlKey. You can check this to look if the key was pressed or not. See snippet below for more control like keys.
function detectspecialkeys(e){
var evtobj=window.event? event : e
if (evtobj.altKey || evtobj.ctrlKey || evtobj.shiftKey)
alert("you pressed one of the 'Alt', 'Ctrl', or 'Shift' keys")
}
document.onkeypress=detectspecialkeys