Is there a way to have XmlDocument.SelectSingleNode to ignore case?

I have a webservice and sometimes people send me requests that don't match the case of the tags. Is there a way to ignore case when using SelectSingleNode.

I can make their entire input string to lower, but then that would also affect the values in the tags. Any easier way to do this....                

XmlDocument xmlDocInput;
value = xmlDocInput.SelectSingleNode("Document/Value").InnerText;