ul.nav{
  float: left;
  width: 200px;
  list-style: none;
  margin: 0;
  padding: 0;
}

ul.nav li{
  float: left;
  margin: 13px 0 0 0;
  padding: 0; 
}
.nav_01{
  float: left;
  background: url('imgs/nav_mission_statement.gif');
}

a.nav_01{
  background: url('imgs/nav_mission_statement.gif');
}

a.nav_01:hover{
  background: url('imgs/nav_mission_statement_over.gif');
}

.nav_02{
  float: left;
  background: url('imgs/nav_our_practice.gif') no-repeat;
}

a.nav_02{
  background: url('imgs/nav_our_practice.gif') no-repeat;
}

a.nav_02:hover{
  background: url('imgs/nav_our_practice_over.gif') no-repeat;
}

.nav_03{
  float: left;
  background: url('imgs/nav_meet_our_staff.gif') no-repeat;
}

a.nav_03{
  background: url('imgs/nav_meet_our_staff.gif') no-repeat;
}

a.nav_03:hover{
  background: url('imgs/nav_meet_our_staff_over.gif') no-repeat;
}

.nav_04{
  float: left;
  background: url('imgs/nav_patient_services.gif') no-repeat;
}

a.nav_04{
  background: url('imgs/nav_patient_services.gif') no-repeat;
}

a.nav_04:hover{
  background: url('imgs/nav_patient_services_over.gif') no-repeat;
}

.nav_05{
  float: left;
  background: url('imgs/nav_technology.gif') no-repeat;
}

a.nav_05{
  background: url('imgs/nav_technology.gif') no-repeat;
}

a.nav_05:hover{
  background: url('imgs/nav_technology_over.gif') no-repeat;
}
.nav_06{
  float: left;
  background: url('imgs/nav_financial.gif') no-repeat;
}

a.nav_06{
  background: url('imgs/nav_financial.gif') no-repeat;
}

a.nav_06:hover{
  background: url('imgs/nav_financial_over.gif') no-repeat;
}

.nav_07{
  float: left;
  background: url('imgs/nav_contact.gif') no-repeat;
}

a.nav_07{
  background: url('imgs/nav_contact.gif') no-repeat;
}

a.nav_07:hover{
  background: url('imgs/nav_contact_over.gif') no-repeat;
}
.nav_08{
  background: url('imgs/nav_forms.gif') no-repeat;
}

a.nav_08{
  float: left;
  background: url('imgs/nav_forms.gif') no-repeat;
}

a.nav_08:hover{
  background: url('imgs/nav_forms_over.gif') no-repeat;
}