createtaskwithcontenttype task creation error in sharepoint 2010

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C#

SharePoint

Hi Friends,

I'm new to sharepoint 2010. in my organization they given one small workflow to do.
I created the state machine workflow in visual studio and deployed in sharepoint .

i used create task to create task by default content type.But now i want to use createtaskwithcontenttype.I replaced createtask with createtaskwithcontenttype and also gave the contenttype id.but when i deploy that its showing error occured in workflow.
Please help to resolve this i am struggling to resolve this issue.

this is the code in createtaskwithcontenttype invoking:

private void createTaskWithContentType1_MethodInvoking(object sender, EventArgs e)
        {

            createTaskWithContentType1_TaskProperties1 = new SPWorkflowTaskProperties();
            createTaskWithContentType1_TaskId1 = Guid.NewGuid();
         //   createTaskWithContentType1_ContentTypeId1 = "0x0108003A026B8335DC724AAA9A3A7D81A12F5B";
            createTaskWithContentType1_TaskProperties1.Title = "Approve Document(CType)";
            createTaskWithContentType1_TaskProperties1.AssignedTo = @"domain\name";
            createTaskWithContentType1_TaskProperties1.DueDate = DateTime.Now.AddDays(1.0);
        }

thanks and regards,
jyothi