Cannot set minHeight and minWidth in SimpleModal jQuery plugin

I have read from documentation how can I set minheight and minwidth of modal dialog.

$("#sample").modal({
    minHeight:400,
    minWidth: 600
});

However, even if I rewrite the sample html from

<a href='#' class='basic'>Demo</a> 

to

<a href onclick="$('#basic-modal-content').modal({ minHeight: 1000, minWidth: 1000 });" >Demo</a> 

Modal dialog has still the same default width and height. Am I missing something ?

I had similar experience using version 1.3.5. However, I set the width and the height in the basic.css to be auto and that seemed to solve the problem