Report Parameters Problem

[Ahmed]

I'm using Q3 2010
I have a report with a parameter
First, I need this parameter to be not essential
I mean if it is empty the report displays all the data from the data source

Second,
When I try to apply a filter with a 'Like' operator it gives me an error like this
http://i56.tinypic.com/zy7rs2.jpg

and this applies to some other operators too
So, I tried to apply the filter programmatically like this

this.Filters.Add("=Fields.Name", Telerik.Reporting.Data.FilterOperator.Like, "=Parameters.paraName.Value");

in the report constructor

But when I run the report
it makes the filter as an '='
I mean it returns the records only when the parameter value is exactly the same

[Ahmed]

no reply?