Can someone review/correct this please?

@{
var amount = Request["amount"];
var source_currency = Request["source_currency"];
var target_currency = Request["target_currency"];
var result = "";

string serverURL =@"http://download.finance.yahoo.com/d/quotes.csv?s="+source_currency+target_currency"=X&f=l1";;

result = serverURL*amount, 2;
}