//eo_MaskedEdit_IsValid is the function that MaskedEditValidator
//calls to check whether the input is valid. Here you are redefining
//this function so that your customized version, instead of the
//built-in version is called
function eo_MaskedEdit_IsValid(val)
{
    if (typeof("eo_GetObject") == "undefined")
        return true;
	
    var maskedEdit = eo_GetObject(val.controltovalidate);
    if (!maskedEdit)
        return true;
	
    //Check whether user has entered anything. Returns true
    //to indicate the input is valid if user has NOT entered
    //anything	
    var text = maskedEdit.getText();
    if (text == "   -  -    ")
        return true;

    //If user has entered anything, ask the maskedEdit to
    //check whether the input is valid (whether it matches
    //the mask)
    return maskedEdit.isValid();
}