Having trouble buying on GDAX- warning I am a newb

[Jeff701]

HI there,

Newb here so bare with me,  I catch on quick though.

I have a Coinbase and GDAX account setup.

I loaded up my BTC in GDAX and want to do a Buy with a Limit and it keeps telling me I have insufficient funds.

The amount I'm looking to buy is less or equal to the amount I have in my BTC in my GDAX account so what gives?

I want to trade but obviously I am doing something wrong.  Please help.

Thanks

Jeff