Provide the theme summaries for the following conversation: 

Agnes: good morning. i saw you are selling Zara red dress
Agnes: still available?
Megan: morning! yes, it is
Agnes: could you send me a photo of the back? 
Megan: sure thing
Megan: <file_photo>
Agnes: thank you. how long it is?
Megan: i'm 169 and its knee-length for me
Megan: it's really comfy
Agnes: ok can you book it for me? i will confirm the purchase later today ok?
Megan: okay but plz let me know today

Summary: 
Agnes is interested in buying Zara red dress from Megan. The dress is knee-length for Megan who is 169 cm tall. Megan booked the dress for Agnes, but she asked her to let her know no later than today.