OllyDbg : 'Label expected' issue

Well, as newbie in reverse engineering, i tried to use 'inline patch' technique to patch the program, then i got stuck on this point :

Assemble window keep giving me message 'Label expected', so i edit that instruction to name label, such as 'myfunc'.

But when i tried to assemble codes like 'MOV ECX, 0C', it worked properly.

Why 'Label expected pop up and how to solve this issue?

(Program i'm trying to patch is ap0x's patchme_no1.exe)

Question Number one remove the unpackme. and enter pure address
the string "unpackme.40xxxx" is treated as label
ollydbg tries to locate the label and fails

if you want to use it as it is
you can label some address with that string using the COLON : keyboard shortcut

below are two screen shots one with the error other no error because the address has been labelled for reference

label expected error

the address is labelled now this label can be used in assemble dialog

for second question in comment

you cannot assemble an ascii string inplace
you need to use ctrl+e to edit