.tb4 {  border: solid; border-width: 1px 1px 0px 0px; border-color: #CCCCCC #CCCCCC black black}
.a2 {  border: #000000; border-style: solid; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 1px; border-left-width: 0px}
.a3 {  border: #000000 solid; border-width: 0px 0px 0px 1px}
.a4 {  border: #CCCCCC; border-style: solid; border-top-width: 1px; border-right-width: 1px; border-bottom-width: 1px; border-left-width: 1px}
.a5 {  border: #CCCCCC; border-style: solid; border-top-width: 1px; border-right-width: 1px; border-bottom-width: 0px; border-left-width: 1px}
.a6 {  border: #CCCCCC; border-style: solid; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 1px; border-left-width: 0px}
.a7 {  border: #000000; border-style: solid; border-top-width: 0px; border-right-width: 1px; border-bottom-width: 0px; border-left-width: 0px}