Here's my old script I did awhile back to convert currency I just made a quick dialog to go with it

Code:
alias currency { 
  if ($dialog(currency)) { %cur.c = $$did(currency,11) | %cur.a = $$did(currency,1) | %cur.b = $$did(currency,2) | sockopen currency www.gocurrency.com 80 }
  else { echo 4 -a ERROR: dialog is not open to calculate currency }
}
alias curr { dialog -m currency currency }

on 1:sockopen:currency:{
  .sockwrite -n currency GET $+(/v2/dorate.php?inV=,%cur.c,&from=,%cur.a,&to=,%cur.b) HTTP/1.1
  .sockwrite -n currency HOST: www.gocurrency.com
  .sockwrite -n currency $crlf
}

on 1:sockread:currency:{
  if ($sockerr > 0) return 
  var %x | sockread -fn %x
  if (Dollar(S) isin %x) { 
    did -ra currency 5 $nhtml(%x)
  }
  if ($chr(61) == $gettok(%x,3,32)) && (!%curr.d) {
    did -ra currency 7 $nhtml(%x) | %curr.d = 1 
  }
  elseif ($chr(61) == $gettok(%x,3,32)) && (%curr.d == 1) {
    did -ra currency 8 $nhtml(%x) | unset %curr.d 
  }
}

alias -l nhtml { return $remove($regsubex($1-,/(&nbsp;|&deg;|^[^<]*>|<[^>]*>|<[^>]|&nbsp;*$)/g,),$chr(9)) }

dialog currency {
  title "Currency Convertor"
  size -1 -1 307 67
  option dbu
  combo 1, 96 3 35 50, sort drop
  combo 2, 150 3 35 50, sort drop
  text "Convert:", 3, 68 3 25 8
  text "To:", 4, 134 3 13 8
  edit "", 5, 190 19 116 10, read autohs
  button "Convert", 6, 190 3 115 12, flat
  edit "", 7, 190 40 116 10, read autohs
  edit "", 8, 190 50 116 10, read autohs
  text "Exchange Rate:", 9, 227 30 41 8
  text "Amount:", 10, 5 3 22 8
  edit "", 11, 29 2 36 10
}

on *:dialog:currency:*:*:{
  if ($devent == init) {
    did -a $dname 1,2 EUR 
    did -a $dname 1,2 USD
    did -a $dname 1,2 GBP 
    did -a $dname 1,2 JPY 
    did -a $dname 1,2 INR 
    did -a $dname 1,2 NZD 
    did -a $dname 1,2 CHF 
    did -a $dname 1,2 ZAR
    did -a $dname 1,2 AFN  
    did -a $dname 1,2 ALL  
    did -a $dname 1,2 DZD 
    did -a $dname 1,2 ARS 
    did -a $dname 1,2 AUD 
    did -a $dname 1,2 ATS
    did -a $dname 1,2 BSD 
    did -a $dname 1,2 BHD 
    did -a $dname 1,2 BDT 
    did -a $dname 1,2 BBD
    did -a $dname 1,2 BEF
    did -a $dname 1,2 BMD
    did -a $dname 1,2 BRL 
    did -a $dname 1,2 BGN 
    did -a $dname 1,2 CAD  
    did -a $dname 1,2 XOF 
    did -a $dname 1,2 XAF 
    did -a $dname 1,2 CLP
    did -a $dname 1,2 CNY 
    did -a $dname 1,2 COP
    did -a $dname 1,2 XPF  
    did -a $dname 1,2 CRC 
    did -a $dname 1,2 HRK
    did -a $dname 1,2 CYP 
    did -a $dname 1,2 CZK 
    did -a $dname 1,2 DKK  
    did -a $dname 1,2 DEM  
    did -a $dname 1,2 DOP 
    did -a $dname 1,2 NLG 
    did -a $dname 1,2 XCD  
    did -a $dname 1,2 EGP  
    did -a $dname 1,2 EEK  
    did -a $dname 1,2 FJD 
    did -a $dname 1,2 XAU 
    did -a $dname 1,2 XAG
    did -a $dname 1,2 XPT 
    did -a $dname 1,2 XPD
  }
  elseif ($devent == sclick) {
    if ($did == 6) && ($did($dname,11) isnum) { currency }
  }
}


if you want just to have an alias base on what is asked with updated info all the time then this...

Code:
alias CurrencyConvert {  %cur.c = $$1 | %cur.a = $$2 | %cur.b = $$3 | sockopen currency www.gocurrency.com 80 | halt }

on 1:sockopen:currency:{
  .sockwrite -n currency GET $+(/v2/dorate.php?inV=,%cur.c,&from=,%cur.a,&to=,%cur.b) HTTP/1.1
  .sockwrite -n currency HOST: www.gocurrency.com
  .sockwrite -n currency $crlf
}

on 1:sockread:currency:{
  if ($sockerr > 0) return 
  var %x | sockread -fn %x
  if (Dollar(S) isin %x) { 
    echo -a $gettok($nhtml(%x),5-7,32)
  }
}

alias -l nhtml { return $remove($regsubex($1-,/(&nbsp;|&deg;|^[^<]*>|<[^>]*>|<[^>]|&nbsp;*$)/g,),$chr(9)) }


It will read from site using $currencyconvert(n,from,to)