更改弹出框的顶部

In My code I am using Smarty to display a pop-up in (.tpl) file.
I am using following function for pop-up.

popUpLightBox( $intWidth, $intHeight, url, 'Title of popup');

in my code i am using CLightBox.class.js Liabrary. In which the Top and Left of Pop-up
window is set internally by CLightBox.class.js liabrary.
and due to this each time i ain't get fixed position of pop-up. CLightBox.class.js use
below code to set left and top.
this.intLeft = (Math.round((this.intViewportWidth - this.intCurrentWidth)/2) + 250);
this.intTop = (Math.round((this.intViewportHeight - this.intCurrentHeight)/2) + 192);

Here, viewport width and height is set according to the data rows in the tpl file .

Does anybody can help me to reset its Top by using jQuery or using javascript.
Any type of help is welcomed. Thanks!