function convert(form){

if(form.conv.selectedIndex==0)conv=0

if(form.conv.selectedIndex==1)conv=1;

var given=eval(form.given.value);

var swap=eval(form.swap.value)

if(form.curr.selectedIndex==0)var x=0

if(form.curr.selectedIndex==1)var x=0

if(form.curr.selectedIndex==2)var x=0

if(form.curr.selectedIndex==3)var x=1

if(form.curr.selectedIndex==4)var x=1

if(form.curr.selectedIndex==5)var x=1

if(conv==0){

if(x==0){

 var ans=eval(1.0/given-swap);

}

if(x==1){

 var ans=eval(given-swap);

}

}

if(conv==1){

if(x==0){

 var ans=eval(1.0/(given+swap));

}

if(x==1){

 var ans=eval(given+swap);

}

}



form.answer.value=ans;}