html option in form_for errors

Hello, everyone:      I tried the html option (multipart) to upload an image to server , but the form_for always errors. If I remove the html option, it works. I have no idea the reason, looks like it is only a syntax error, but couldn't figure it out.     Thanks a lot in advance!

Br, Myst

Hello, everyone:     I tried the html option (multipart) to upload an image to server , but the form_for always errors. If I remove the html option, it works. I have no idea the reason, looks like it is only a syntax error, but couldn't figure it out.    Thanks a lot in advance!

form_for([@task, @comment], :html => {:multipart => true})

Thank you ..... again, frederick.. now, I knows what stupid mistake I've made