I am using jquery uimodaldialog and this is setting

$("#dialog").dialog({
    autoOpen : false,
    minWidth : 700,
    show : {
        effect : "fade",
        duration : 1000
           },
    hide : {
        effect : "fade",
        duration : 1000
           },
    close : function(event, ui) {
    },
});

I am calling with this

 $('.mylink').on('click', function() {
 $( "#dialog" ).dialog( "open");

Now on first click it shows at center of page .

if I click again then it goes about 200px upwards.

On further clicking it says there