Syntax

=VLOOKUP(lookup_value,table_array,col_index_num,range_lookup)

in your case the lookup value is the name the table array is your whole
database with names AND fax numbers,col index number is presumably 2 and
range lookup will befalse since you want to look for an exact match of your
name

so just say your name and fax numbers are in the rangeA1:B10,no headers or
labels to the top or left  and you type or select the name you want to find
in cell d1 your lookup formula will be =vlookup(D1,A1:B10,2,false)

Lookup_value    is the value to be found in the first column of the array.
Lookup_value can be a value, a reference, or a text string.

Table_array    is the table of information in which data is looked up. Use a
reference to a range or a range name, such as Database or List.

If range_lookup is TRUE, the values in the first column of table_array must
be placed in ascending order: ..., -2, -1, 0, 1, 2, ..., A-Z, FALSE, TRUE;
otherwise VLOOKUP may not give the correct value. If range_lookup is FALSE,
table_array does not need to be sorted.

You can put the values in ascending order by choosing the Sort command from
the Data menu and selecting Ascending.

The values in the first column of table_array can be text, numbers, or
logical values.

Uppercase and lowercase text are equivalent.

Col_index_num    is the column number in table_array from which the matching
value must be returned. A col_index_num of 1 returns the value in the first
column in table_array; a col_index_num of 2 returns the value in the second
column in table_array, and so on. If col_index_num is less than 1, VLOOKUP
returns the #VALUE! error value; if col_index_num is greater than the number
of columns in table_array, VLOOKUP returns the #REF! error value.

Range_lookup    is a logical value that specifies whether you want VLOOKUP
to find an exact match or an approximate match. If TRUE or omitted, an
approximate match is returned. In other words, if an exact match is not
found, the next largest value that is less than lookup_value is returned. If
FALSE, VLOOKUP will find an exact match. If one is not found, the error value
#N/A is returned.