#div_1{}
#div_2{visibility: hidden; display: none;}
#div_3{visibility: hidden; display: none;}
#div_4{visibility: hidden; display: none;}

#div_1 a, #div_2 a, #div_3 a, #div_4 a {
	text-decoration: none;
}

#div_1 a:hover, #div_2 a:hover, #div_3 a:hover, #div_4 a:hover{
	text-decoration: none;
}