Passing a VB string to a Crystal parameter field

Hello,
I'm having trouble passing a VB string to a Crystal Report parameter field. Following is an excerpt of the code:
----------------
strDocID = InputBox("Please enter the DocID")

If strDocID <> "" Then
With CrystalReport1
.ReportFileName = "C:\Program Files\CSC Imaging\CSCReports\Reports\DocumentHistory.rpt" .Connect = cn.ConnectionString
.WindowState = crptMaximized
strSelection = "{CSC_TRANS.Document_ID} = " & "'" + strDocID + "'"
.ReplaceSelectionFormula strSelection
.Destination = crptToWindow
.Action = 1
----------------

The user enters the DocID, but when the Crystal Report launches, the user has to enter it again.

Following is the entry in the Record Selection Formula:
{CSC_TRANS.Document_ID} = {?DocumentID_PROMPT}

Also, if they select Cancel in the Crystal parameter window, it still tries to run the report. How can I stop the report from running?

Thank you for your assistance!
Andyeither is wrong the formula,and is crystal report,doesn't know the field. or...
work with an report object,and put
Public reportApp As CRAXDRT.Application
Public Report As CRAXDRT.Report

reportApp=createobject("CRAXDRT.Application")
report=reportApp.loadReport("...rpt")
...for not showing parameter prompting
Report.EnableParameterPrompting=false
report is an object of craxdrt.dll i thing at least i have worked with this one.this is for not showing the parameters inputs again.
also,it should be existing in the report(in design) a parameter(Insert/Parameter) and the value for that should have your docID value
something like this.
Dim cpars As CRAXDRT.ParameterFieldDefinitions
Dim cpar As CRAXDRT.ParameterFieldDefinition
Set cpar = cpars(1)
cpar.AddCurrentValue (docID)
docID here is your VB variable

Maybe this will work,or try to verify carefully the selection formula,AND in report it should be existing a parameter that will take in the code that value!

Good luck|||Thank you very much for the reply, jasie24!