How to pass string to atl com dll from visual c#

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Hi,

What data type(wchar or bstr or variant) I have to give for string in
atl com dll which will use in asp.net aplication and code-behind is visual c#?

code snippet:
STDMETHODIMP CMyTest::TestStringFunc(BSTR bstrFilesInfo)
{
// TODO: Add your implementation code here
return S_OK;
}
In Visual C#, what data type I have to take to send the string data to
atl com dll?

protected void Button1_Click(object sender, EventArgs e)
{
MyTestClass obj = new MyTestClass();
obj.TestStringFunc("hi welcome to visual c#"); //application getting
crash here.
Response.Write("Durga...4");
}
//error info:Attempted to read or write protected memory. This is often an
indication that other memory is corrupt.

Thanks in advance.

--
Thanks & Regards,
John.

[Brian Muth]

Answered elsewhere. So far I've counted 3 multiposts.

Brian