To set Decimal value in Text Box with Decimal Type in InfoPath

Use this code for setting the value in the Decimal type text box in InfoPath

XPathNavigator XMLDom = MainDataSource.CreateNavigator();
//Text Box Xpath
XPathNavigator XMLValue = XMLDom.SelectSingleNode("/my:myFields/my:DecimalValue", NamespaceManager);

if (XMLValue.MoveToAttribute("nil", "http://www.w3.org/2001/XMLSchema-instance"))
{
XMLValue.DeleteSelf();
}
XMLValue.SetValue("10.00");//Set the value
XMLDom=null;
XMLValue = null;