You have to use trading view ( on new order tab click "New Charting & Trading Tools"). Choose your pair and after clicking on your funds (the number) entire balance is used.
Thanks for the tip. Seems like I was able to buy some Dash yesterday after all (using the manual approach, trying to calculate the amount of Dash I could buy from my bitcoin holdings), even though I got what some error messages. But next til I'll use the new trading view (aka cryptowat.ch) - it looks great!
You're welcome. I don't know why I said trading view when it's cryptowatch
. Never mind.
FYI myself found it pretty buggy. Lot of times the ordes just does not get processed. Don't know if the issue is on my or the server side.