INSTR Function Details
 
Syntax
  INSTR([start,]stringexpression1,stringexpression2)
 
  Argument            Description
  start               An optional offset that sets the position for
                      starting the search; start must be in the range
                      1-32,767. If start is not given, the INSTR
                      function begins the search at the first
                      character of stringexpression1.
  stringexpression1   The string being searched.
  stringexpression2   The string to look for.
 
The arguments stringexpression1 and stringexpression2 can be string
variables, string expressions, or string literals.
 
The value returned by INSTR depends on the following conditions:
 
  Condition                           Value Returned
  stringexpression2 found in          The position at which the
  stringexpression1                   match is found
 
  start greater than length of        0
  stringexpression1
 
  stringexpression1 is null string    0
 
  stringexpression2 cannot be found   0
 
  stringexpression2 is null string    start (if given); otherwise, 1
 
Use the LEN function to find the length of stringexpression1.