143=I love you (one letter, four letters, three letters. see it now?)
831=I love you (eight letters, three words, one meaning)
637=Always and forever (six letters, three letters, seven letters)
823=Thinking of you (eight letters, two letters, three letters)
99=Night night (the way the nine sounds)
143-637-823-247=I love you always and forever thinking about you 24 hours and 7 days a week

a=8
b=8
c=6
d=0
e=3
f=9
g=6 or 9
h=4
i=1
j=7
k=15
l=7
m=177
n=17
o=0
p=9
q=2 or 0
r=12
s=5
t=7
u=11
v=11
w=111
x=96
y=4
z=2