usage of functions in mysql (n00b)

I want to compute one variable from another variable in the same table
original variable is ip (varchar 50)
variable to be computed is ip_aton (bigint)

I seem to have opened the database correctly, the following statement executes OK (it is just a test without real meaning, it bumps counters for all ip).

mysql_query("UPDATE $table_name SET visits=visits+1 WHERE 1=1;");

Code (markup):

However, when I try to compute the variable ip_aton, using the function INET_ATON I only get 0 in the column for ip_aton. I think I must have misunderstood how to use the function INET_ATON?

mysql_query("UPDATE $table_name SET ip_aton=INET_ATON('ip') WHERE 1=1;") or die(mysql_error());

Code (markup):

Thanks

 

I apologise for beginner's mistake. I should not have single quotes around ip when calling the function.
Thread solved
Sorry.

EDIT:

mysql_query("UPDATE $table_name SET ip_aton=INET_ATON(ip) WHERE 1=1;") or die(mysql_error());

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