Crystal reports update parameter

Hi,

I have a crystalreportviewer on my form, I'd like to from a button on the form be able to update my report with a new parameter value once the report is already loaded, is there a way to change the parameter value in realtime through code, such as if I were to press the refresh button?

    
    Dim param1Fileds As New CrystalDecisions.Shared.ParameterFields
        Dim param1Field As New CrystalDecisions.Shared.ParameterField
        Dim param1Range As New CrystalDecisions.Shared.ParameterDiscreteValue

        param1Field.ParameterFieldName = "emp"
        param1Range.Value = "Phil" ' value For Parameter Field 
        param1Field.CurrentValues.Add(param1Range)
        param1Fileds.Add(param1Field)
        CrystalReportViewer1.ParameterFieldInfo = param1Fileds 'to pass parameter inf.to CRV
        CrystalReportViewer1.Refresh()

        Dim param1Fileds1 As New CrystalDecisions.Shared.ParameterFields
        Dim param1Field1 As New CrystalDecisions.Shared.ParameterField
        Dim param1Range1 As New CrystalDecisions.Shared.ParameterDiscreteValue

        param1Field1.ParameterFieldName = "emp"
        param1Range1.Value = "Carl" ' value For Parameter Field 
        param1Field1.CurrentValues.Add(param1Range1)
        param1Fileds1.Add(param1Field1)
        CrystalReportViewer1.ParameterFieldInfo = param1Fileds1 'to pass parameter inf.to CRV
        CrystalReportViewer1.Refresh()