Paypal check out page missing variable

I hope somebody can help me with this. I’ m working on a donation page for a non profit and need to code a Paypal donation button. I got it to work fine except for adding the text field for special instructions, in this case the cause that people want to donate for.

I changed the no_note value to 0 , declared a private var cause and assigned it a value of “Enter project you want to sponsor” and then called it with the other paypalVars as part of the thisClick function, paypalVars.cn=cause;

I also tried not declaring a var at all, since with no_note =0 the default “Add special instructions to merchant.” should show up.

I tried everything else I could think of, but the prompt is still not showing up. Please help!

I could post my code if that helps, just let me know.

TIA