can i save the file as .php or php file?

can i save the file as .php or as php file?...or is it limited only to .htm?..
i have to get my data to be displayed on the grid in my database..
for instance the data that i should have to place in the grid are comes from mysql... does grid allows that? or can it read a php code?...

my code goes like this...

<script>
var myData = [
<?foreach($rows as $r)
{?>
[<?echo "$r[applicantID]","$r[fname]";?>],
<?}?>
];
var myColumns = [
"applicantNo.", "Name"
];
</script>

can those be possible?... or those kind of codes can be possible?...