Hi Vishal,

If you are using a lookup window to find a contact, what about creating a custom lookup window to which you add a "create contact" button. Use the create button to replace the lookup content with new contact fields right in that window, simple as re-rendering the page using render flags. That way its in keeping with standard salesforce UX and your users will possibly embrace the custom functionality more easily.

The only moderately difficult part is getting the selection back from the child lookup window to the parent.

These functions go on the parent VF page:

function openPopupFocus(a, b, c, d, e, f, g, k) {
    closePopup();

    if (f) {
        if (lastMouseX - c < 0) 
            lastMouseX = c;
        if (lastMouseY + d > screen.height) 
            lastMouseY -= lastMouseY + d + 50 - screen.height;
        lastMouseX -= c;
        lastMouseY += 10;
        e += ",screenX=" + lastMouseX + ",left=" + lastMouseX + ",screenY=" + lastMouseY + ",top=" + lastMouseY
    }

    curPopupWindow = window.open(a, b, e, false);
    curPopupWindow.focus()

    if (k) 
        closeOnParentUnloadWindow = win
}

function closePopup() {
    if (closetimer) {
        clearTimeout(closetimer);
        closetimer = null
    }
    if (curPopupWindow != null) {
        try {
            if (curPopupWindow.confirmOnClose) if (curPopupWindow.confirm(curPopupWindow.confirmOnCloseLabel)) {
                curPopupWindow.confirmOnClose = false;
                curPopupWindow.focus();
                return false
            }
            curPopupWindow.close()
        } catch (a) {}
        curPopupWindow = null
    }
}

Link to open the window

openPopupFocus(%27/apex/<VF PAGE NAME>?filter=item%27, %27CCBCCLookup%27, 420, 490, %27width=420,height=490,toolbar=no,status=no,directories=no,menubar=no,resizable=yes,scrollable=no%27, true);​

This function goes on the custom lookup page:

function sendToParent(selectedId,selectedName){

        top.window.opener.doLookupPick(<hidden field dom id>,
                                         <selected sfObject ID>,
                                         <text input field dom id>',
                                         <text input contact name>);


}

Please mark this post as solved if it's resolved.

Best Regards,
Nagendra.P