Verifying image types (jpg, png, gif)

[sc_king]

My Form
echo "Main Image: <br />";
echo "<input name='uploaded[]' type='file' /><br /><br />";
echo "Image 2: <br />";
echo "<input name='uploaded[]' type='file' /><br /><br />";
echo "Image 3: <br />";
echo "<input name='uploaded[]' type='file' /><br /><br />";
echo "Image 4: <br />";
echo "<input name='uploaded[]' type='file' /><br /><br />";

I will pass the array uploaded into my function.
How can I verify the types to only include those which I have mentioned?

[toenailsin]

is this what your looking for?

$File_Extension = strtoupper(ereg_replace(".*\.(.*)$","\\1", $FileName));

[NogDog]

getimagesize (http://www.php.net/getimagesize)() can be used to determine most common types of image files.

[sc_king]

Will these allow me to find if a person uploaded a wrong filetype?

Is this the best way?

[NogDog]

getimagesize() is probably the most complete method (within the built-in PHP functions). It actually analyzes the file contents, rather than just looking to see what the file suffix is.