Below is part of my code which positions the table where i want on the page with $xdata and $ydata variables. both variables read from a textfile with a number in it, i was wondering how can i refresh the variables information every 5 seconds so if i change the numbers in the text file the table will automatically move to the position on the screen with the updated information:

Code:
<table border="0" cellspacing="0" cellpadding="0" id="userdatatable" style="position: absolute; left: <?= $xdata ?>; top: <?= $ydata ?>">