Detect if Shift is pressed

Question

I have a situation on a phone field. On this field, the user can type the following phone numbers:

(00)9999 9999
(00)99999 9999 (in São Paulo Brasil)
and 1234*12 (Nextel Numbers)

On the field phone I configure an onkeydown event that call this javascript function:

function validateKeyDownPhone(event) {

    var c = event.keyCode
        keychar=String.fromCharCode(c)
        valid = true

    /**
     * Excluding enter, backspace, etc. 
     */
    if (c > 46 ) {          
        if (keychar != null) {  
            var re = new RegExp("^[0-9\*#\(\) ]+$")
            matched = keychar.match(re)
            valid = matched != null && matched.length > 0
        }
    }
    event.returnValue = valid
}

It works fine, but when the I press SHIFT + 5 results in %, for example.

How can I identify if the shift key was pressed?

Answer 1

The event.shiftKey attribute should tell you that information.