// Permite apenas a digitação de Letras (Alpha)
function somente_letra(e)
{
	var key;
	var keychar;

	if (window.event)
		key = window.event.keyCode;
	else if (e)
		key = e.which;
	else
	return true;

	keychar = String.fromCharCode(key);
	keychar = keychar.toLowerCase();

	// teclas de controle
	if ((key==null) || (key==0) || (key==8) || (key==9) || (key==13) || (key==27) ) return true;

    // letras
	else if ((("abcdefghijklmnopqrstuvwxyz ").indexOf(keychar) > -1)) return true;

        return false;   
}

// Permite apenas a digitação de Numeros (Num)
function somente_numero(e)
{
	var key;
	var keychar;
	
	if (window.event)
	   key = window.event.keyCode;
	else if (e)
	   key = e.which;
	else
	   return true;
	keychar = String.fromCharCode(key);
	
	// teclas de controle
	if ((key==null) || (key==0) || (key==8) || 
		(key==9) || (key==13) || (key==27) )
	   return true;
	
	 // números
	else 
	if ((("0123456789").indexOf(keychar) > -1))
		return true;
		else
	return false;
}

function letra_numero(e)
{
	var key;
	var keychar;

	if (window.event)
		key = window.event.keyCode;
	else if (e)
		key = e.which;
	else
	return true;

	keychar = String.fromCharCode(key);
	keychar = keychar.toLowerCase();

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

	else if ((("abcdefghijklmnopqrstuvwxyz ").indexOf(keychar) > -1)) return true;
	else if ((("0123456789").indexOf(keychar) > -1))
	   return true;

	return false;   
}