The default behavior will not allow for such a format, however you could use the AfterValueChanged client side event in order to achieve the result you desired. Attached is the sample we used for such scenario

Unfortunately, the latest version of WebMenuBar MenuCommand default behavior must be clicked in order to open up. A workaround, by simulating the onClick event during mouse over can be achieved using this snippet:

var id = "";
    
function init()
{
    setTimeout(function()
    {
        var menuBar = ISGetObject("WebMenuBar1");

        for (var i = 0; i < menuBar.Menus.length; i++)
        {
            Listener.Add(menuBar.Menus[i]._HtmlObj, "onmouseover", showMenuCommand, menuBar.Menus[i]);
        }
    }, 500);
}

function showMenuCommand()
{
    if (id != this.Name)
    {
        id = this.Name;
        this.OnClick();
    }
}

The Init() function should be invoked during window onload client side event.

The issue will be solved if you are using HTML doctype.

However, if you wish to use XHTML doctype, You will need to use this workaround, removing the float left property from the WebCombo frame element during initialize client side event, for WebCombo2 in your attached sample. 

function WebCombo2_OnInitialize(controlId)
{
	var WebCombo2 = ISGetObject(controlId);
	WebCombo2.GetFrameElement().parentElement.style.styleFloat = "";
	    
	return true;
}

The issue you mention regarding the WebCombo shrinks on mouse over could not be replicated using the latest WebCombo 4 and WebUI Framework 3, build 218 and 750

Regarding issue #2, you will need to invoke the DoResize() method if you wish to use the XHTML doctype.

Thanks for the info. I think if the Width property is not assignedthen it should not override the class by setting the width element. By doing so, you can't really customize this without exposing a Width property on a control derived from WebInput, i.e., cannot completely drive it with a style sheet. Thanks.

Thank you for the suggestion, I will discuss you concern with the develo[er for implementation in the future release of WebInput.

An article regarding this scenario has been detailed in article titled "Walkthrough: Adding custom fields in WebScheduler using Extensibility feature" on the WebScheduler documentation. The sample has been provided as EventOrganizer.aspx in the WebScheduler sample.

Based on the snippet you provided, you already add a new field in the EditingForm and create the inheritance class of the Event and Resouce. However the article has also detailed the necessary setting that you will need to apply to the WebScheduler.