Pig filter OR operator
<pre><code>a = load '/user/home/samp.txt' using PigStorage(',');
dump a;
(2008-Jan-12,12.1,13.1,36.0)
(2008-Jan-13,13.1,14.1,45.00)
(2008-Jan-15,14.2,15.2,47.00)
(2008-Jan-16,16.1,17.1,47.5)
(2008-Jan-12,8.5,17,50,12.0)
(2008-Jan-12,n#/a,n#/a,n#/a)
(2008-Jan-19,n#/a,n#/a,n#/a)
(2008-Jan-12,n#/a,n#/a,27)
(2008-Jan-12,n#/a,13.00,n#/a)
b = filter a by ($1!='n#/a' OR $2!='n#/a' OR $3!='n#/a');
dump b;
(2008-Jan-12,12.1,13.1,36.0)
(2008-Jan-13,13.1,14.1,45.00)
(2008-Jan-15,14.2,15.2,47.00)
(2008-Jan-16,16.1,17.1,47.5)
(2008-Jan-12,8.5,17,50,12.0)
(2008-Jan-12,n#/a,n#/a,27)
(2008-Jan-12,n#/a,13.00,n#/a)
</code></pre>

<p>why still iam getting <code>"n#/a"</code> in b</p>