There is a term of endearment in vietnamese, somewhat meaning "sweetheart" or "darling" or something to that effect, pronounced "Em" or "Ehm" in english (reversal female-to-male being pronounced "Uhn" or "Ahn" apparently?)... If there is anyone who knows what I am talking about, and how to spell it, in vietnamese? (not sure if the vietnamese alphabet works on Y!A, but maybe just describe the character, or reference another website?) It would be a huge help, as I could actually write it in a letter and make my lady blush, w/o the hassle of having to ask her to spell it for me...

I want to imply to my sweetheart both the emotional and physical heart if you can do that. If not, then the physical heart.and the emotional or loving heart separately.
1, Your loving heart is precious to me
2, Your heart is precious to me
3, Come back (to me) soon
4, I will miss you sweetheart

How do you say "Hello sweetheart" in Vietnamese? Thanks!