img,
.tab a{
	user-drag: none; 
	-moz-user-select: none;  
	-webkit-user-drag: none;
}

.icon_number_button:before{
	content: url('../img/SB_L_G10_U02_L0a_icono-preguntas-numeradas.png');
}

.icon_button_next:before{
	content: url('../img/SB_L_G10_U02_L0a_icono-boton-desplazamiento.png');
}

.icon_button:before{
	content: url('../img/SB_L_G10_U02_L0a_icono-boton.png');
}

.icon_button_question:before{
	content: url('../img/SB_L_G10_U02_L0a_icono-pregunta.png');
}