Possible Duplicate:
“a” or “an” for words that don't start with vowels but sound like they're starting with a vowel
Do you use “a” or “an” before acronyms?
Does one use 'a' or 'an' before the word X-Ray?
Use of “a” versus “an”
I understand that "an" has to be used whenever the next word phonetically begins with a vowel. But in this case L.V. is an abbreviation.