function display(item) {

document.all.p1.style.display="none";
document.all.p2.style.display="none";

document.all.a1.href="javascript:display(p1)";
document.all.a2.href="javascript:display(p2)";

 if (item==p1){
 document.all.p1.style.display="";
 document.all.a1.href="javascript:hide(p1)"}
 if (item==p2){
 document.all.p2.style.display="";
 document.all.a2.href="javascript:hide(p2)"}

}

function hide(item){

 if (item==p1){
 document.all.p1.style.display="none";
 document.all.a1.href="javascript:display(p1)"}
 if (item==p2){
 document.all.p2.style.display="none";
 document.all.a2.href="javascript:display(p2)"}

}