Does anyone know what is the proper way to render a rectangle transparent texture over the screen in OpenGL ES 2.0?

Question

Hello I'd like to convert my directx program to ios and I'm stuck right now on rendering textures.
I messed around and enabled otho camera in open gl ES 2.0 and textures render but I can't get alpha to work.
I used glDrawArrays specifying the colour as my colour with the alpha yet it seems to completely ignore the alpha.
Do I need to enable states as with directx?
I'm very new to OpenGL. (if there's any directx to OpenGL tutorials about they might be nice I did buy an OpenGL book but it's all wrong since it uses glVertex3f etc which isn't VBO obviously that won't work for app store apps)

Answer 1

Thank you both guys.
As John said, I believe I'm looking for a gap-free sequence per master record.
The line number of the OrderItems table is the second half of the primary key. The first half of the primary key (DocumentNumber) is the foreign key to the Orders table.
Think of it like line items on an order or invoice. For example, if you were talking to someone on the phone concerning an invoice, you might say, "The pricing for line item #3 is incorrect." In this case, it's good to have a common reference. Or imagine a Microsoft Excel spreadsheet with no row numbers displayed! You'd never get anywhere if you had to explain something over the phone.
If this is tricky to perform, I take it using a sequence and trigger such as the Fusion Order Demo is the best way to approach the challenge for simplicity's sake?
Will