function onlyNumeric(e,extra){
	var key;
	var keychar;
	
	if (window.event)
   	key = window.event.keyCode;
	else if (e)
   	key = e.which;
	else
   	return true;
	keychar = String.fromCharCode(key);
	
	if (typeof(extra)!="undefined") 
		if(keychar == extra) return true;

	// control keys
	if ((key==null) || (key==0) || (key==8) || (key==9) || (key==13) || (key==27) ) return true;

	// numbers
	else if ((("0123456789").indexOf(keychar) > -1)) return true;
	
	else return false;
}

function openingSwitch() {
  toggleDisplay('specialmain');
  toggleDisplay('specialtext');
}

function toggleDisplay(div){
	var state;
	if (document.layers){
		 state = document.layers[div].display;
		 document.layers[div].display = opposite(state);
	}
	else if (document.all) {
		state = document.all[div].style.display;
		document.all[div].style.display = opposite(state);
	}
	else if (document.getElementById) {
		state = document.getElementById(div).style.display;
		document.getElementById(div).style.display = opposite(state);
	}
}

function opposite(state){
	if( state == 'block' )	return 'none';
	else return 'block';
}