problem invoke into web service

Hi, please help me in this error

Server Error in '/EMOS/web' Application.
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Request format is unrecognized.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.InvalidOperationException: Request format is unrecognized.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:


[InvalidOperationException: Request format is unrecognized.]
System.Web.Services.Protocols.WebServiceHandlerFactory.CoreGetHandler(Type type, HttpContext context, HttpRequest request, HttpResponse response)
System.Web.Services.Protocols.WebServiceHandlerFactory.GetHandler(HttpContext context, String verb, String url, String filePath)
System.Web.HttpApplication.MapHttpHandler(HttpContext context, String requestType, String path, String pathTranslated, Boolean useAppConfig) +699
System.Web.MapHandlerExecutionStep.System.Web.HttpApplication+IExecutionStep.Execute() +95
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +173

Hi.

Post your code.
Tell us what you did to get the error.
Show us which line is erroring out.
Realize we're not psychic.