title: Not able to resolve the error in PL/SQL function
body: <p>I'm writing a stored function called MAKE_EMAIL that will accept input arguments for first name and lastname and will return a varchar2 value containing the email address in the form of first initial of the firstname followed by the full last name followed by @hpu.edu.</p>
  
  <p>Ex: Calling:</p>
  
  <pre><code>select make_email('Edward','Souza')
  from dual
  </code></pre>
  
  <p>... would return the single value:</p>
  
  <pre><code>'esouza@hpu.edu'
  </code></pre>
  
  <p>Please consider the following code for a function:</p>
  
  <p>Code:</p>
  
  <pre><code>create or replace function MAKE_EMAIL(lastname varchar2(10),firstname varchar2(10))
   return VARCHAR 
  IS
  
    email VARCHAR2;
  
   BEGIN
  
   email := substr(lastname ,1,1)|| firstname || '@hpu.edu';
  RETURN email;
  
  END;
    /
  </code></pre>
  
  <p>After running above function, I'm getting some errors. Please find the errors below. Please let me know how can I remove these errors or anything wrong with above code?</p>
  
  <pre><code>Warning: Function created with compilation errors.
  
  SQL&gt; show errors
  Errors for FUNCTION MAKE_EMAIL:
  
  LINE/COL ERROR
  -----------------------------------------------------------------
  1/38     PLS-00103: Encountered the symbol "(" when expecting one of the
       following:
       := . ) , @ % default character
       The symbol ":=" was substituted for "(" to continue.
  
  1/61     PLS-00103: Encountered the symbol "(" when expecting one of the
       following:
       := . ) , @ % default character
       The symbol ":=" was substituted for "(" to continue.
  </code></pre>
  
  <p>Here is the link for error:</p>
  
  <p><a href="https://www.dropbox.com/s/gmjhbvie1c7dbcx/Error.png" rel="nofollow">https://www.dropbox.com/s/gmjhbvie1c7dbcx/Error.png</a></p>