Twitter modal positioning - grails

Question

so I'm using the Twitter Bootstrap plugin for Grails and I'm having trouble centering modals. When I remove the class="modal" part from the div that contains the modal, my centering function works properly, but when I put it back (which is necessary for it to have the functionality of a modal it gets stuck halfway off the page). Any help would be very nice :D
Here's my code:
<a style="position: relative; top: 2px;" data-toggle="modal" href="#myModal${instanceType.id}"
id="${instanceType.id}"> ${message} </a>
<div class="modal" style="background: black; overflow: hidden; top: 0px; left: 0px; display: none; border: 2px solid white; float: center; position: absolute"
id="myModal${instanceType.id}">
<div style="border:none" class="modal-header">
<a style="color:white;" class="close" data-dismiss="modal">X</a>
</div>
<iframe id="iFrame" style="border: none;"width=800px height=675px src="${action}/${instanceType.id}">
</iframe>
<div class="modal-body" style="background: black;"></div>
<div style="border:none; background: black;" class="modal-footer">
<a "="#" class="btn" data-dismiss="modal">Close</a>
</div>
</div>
<script>
jQuery.fn.center = function () {
this.css("position","absolute");
this.css("top", ( $(window).height() - this.height() ) / 2+$(window).scrollTop() + "px");
this.css("left", ( $(window).width() - this.width() ) / 2+$(window).scrollLeft() + "px");
return this;
}
$(myModal${instanceType.id}).css({
'width' : $(window).width()*.75,
'height' : $(window).height()*.75
})
$(myModal${instanceType.id}).center()
$('#modal-footer').append('${saveName}')
function submitFunction(){
$("iFrame").contents().find("#submit").click()
}
function changePre(){
$("iFrame").contents().find(".buttonNew").submit()
alert('hi')
}
</script>

Answer 1

If you're using the default modal styling centers the modal by absolute positioning. So when you customize a modal windows, and you change the size of it, you shall adjust relevant elements also. Like the modal-body and modal header and the .modal class.
And to answer your question, and if I got your question right, that is you were trying to position your modal VERTICALLY.
Open bootstrap.css , then find and edit .modal.fade.in
The default value is 50%. Try to play with it until you achieve your desired position. Increase it to move the modal to the bottom, decrease it and it will do the opposite.

Answer 2

Default modal size modal window positions Horizontal centre of the screen, once the modal customizes(width changes), need to position it with script.
sample script:
$('#myModal').modal({
backdrop: true,
keyboard: true
}).css({
width: '800',// custom width
'margin-left': function () {
return -($(this).width() / 2);
}
});