Where is the problem?

Where is the problem? & Lt; body & gt; & lt; form & nbsp; actionindex. php & nbsp; methodpost & gt; input A: & lt; input & nbsp; typetext & nbsp; namec & gt; & lt; br & gt; input B: & lt; where is the problem with input & nbsp; typetext & nbsp; named?

 Function jisuan (& $ a, & $ B ){
$ C = $ a + $ B;
Echo 'a + B = '. $ c ."
";
}
If (isset ($ _ POST ['c']) & isset ($ _ POST ['D'])
{
$ X = $ _ POST ['c'];
$ Y = $ _ POST ['D'];
Jisuan ($ x, $ y );
}
Else
Echo "the result is 0! ";
?>

Always prompts that c and d are not defined. Why?

------ Solution --------------------
The program is normal.
------ Solution --------------------
No errors were found. Paste the complete code and error information.
------ Solution --------------------
The program is normal.
------ Solution --------------------

 Function jisuan (& $ a, & $ B ){
$ C = $ a + $ B;
Echo 'a + B = '. $ c ."
";
}
If (isset ($ _ POST ['c']) & isset ($ _ POST ['D'])
{
$ X = $ _ POST ['c'];
$ Y = $ _ POST ['D'];
Jisuan ($ x, $ y );
}
Else
Echo "the result is 0! ";
?>

Create an index. php file and cut the above file to run the HTML page.
------ Solution --------------------
Reference:

Quote: reference:

Notice can be set to ignore, without affecting the running

How to set it?

Error_reporting (0 );