Web services

Hello! I have a problem:
I have a webservice in c# that have an array of string as parameter.
I want to call it with a coldfusion page, but I can't. I don't know how do it.
I put in my coldfusion page the following code:

<cfscript>

firstName = ArrayNew(1);
ArrayAppend(firstName, "Clara");
ArrayAppend(firstName, "Maria");
ArrayAppend(firstName, "Carlos");

ws = CreateObject("webservice","http://mymachine/WebService1/Service1.asmx?wsdl");

ws.setArray(firstName);

</cfscript>


This code, generate a java.lang.IllegalArgumentException

The webservice has the following code:
[WebMethod]
public void setArray(string[] firstname)
{
for (int i =0;i<firstname.Length; i++)
{
string newName = (String)(firstname.GetValue(i))+"1";
}
}

Thank you very much.
Daniela

Can you post the WSDL of the web service in question?