if you wanted to display in smartforms
when you create simple text , for that text select text type as 'INCLUDE TEXT' and pass parameters i mentioned
OBJECT VBBK
NAME 0000255562 here name is your sales order number
ID 0012
SPRAS EN
here i have hard coded sales order number , get sales order number into a variable and pass to name. and thats it it will display header text on your smartforms.
why dont you try all these things which everyone is suggesting. please make yourself work on all the suggestions mentioned by all experts here.