Vojislav,

Change this

boundary = "----WebKitFormBoundary7MA4YWxkTrZu0gW"   

into this

boundary = "WebKitFormBoundary7MA4YWxkTrZu0gW"   

Then, in the TEXT .. ENDTEXT structure, change all occurrences of the boundary to

--<<m.boundary>>

except for the last one, that must signal the end of form data:

--<<m.boundary>>--

In the request header, set it to

m.loXMLHTTP.setRequestHeader('Content-type', 'multipart/form-data; charset=utf-8; boundary=' + m.boundary)

Also, be sure to calculate the content length after the UTF-8 encoding.

Hopefully, this will do.