endpointConfigurationName error

Hi

I have developed the following code to insert an invoice using API.

Invoice myInvoice = new Invoice ();
myInvoice.InvoiceDate = System.DateTime.Now;
myInvoice.DueDate = System.DateTime.Now;
myInvoice.CustomerReference = "CUST01";

InvoiceLine myInvoiceLine = new InvoiceLine();
myInvoiceLine.Quantity = 1;
myInvoiceLine.Rate = 14;
myInvoiceLine.ChargeType = 4001;


KashFlowAPISoapClient mysoap = new KashFlowAPISoapClient();
string a,b;
try
{
mysoap.InsertInvoice(out a, out b, "sevensoft", "mypassword", myInvoice);
}
catch (Exception ex)
{
Response.Write(ex);
}

I am getting this error

System.Configuration.ConfigurationErrorsException was unhandled by user code
Message="The value of the property 'clientCredentialType' cannot be parsed. The error is: The enumeration value must be one of the following: UserName, Certificate. (E:\\KashFlow\\KashFlow\\web.config line 114)"

on line KashFlowAPISoapClient mysoap = new KashFlowAPISoapClient(); in the above code.

Please help where I am doing wrong?

Nauman