need help on Vugen "Error: C interpreter run time error: Error -- Unresolved symbol : soap_request"

I am running a simple script that use Web Service protocol in Vugen. I used the "soap_request" call and with the input from <soapenv:Body> which I obtained when call the web service using SOAPUI.

It is something like this:

web_set_timeout( "STEP", "180" );

    lr_start_transaction("HDD_IF_getUniqueNcidByRep");
    
    soap_request("StepName=getUniqueNcidByRep",
    "URL={pEndPoint}",
        "SOAPEnvelop="
        "<soapenv:Envelope xmlns:soapenv=\">"   \\ the entire soap envolop goes here
    "<soapenv:Header/>"
    "<soapenv:Body>"
    "<ser:getUniqueNcidByRep>"
    "<representation>Female</representation>"
    "<domainNcid>1209</domainNcid>"
    "contextNcid>2000</contextNcid>"
    "<dbEnv>tst</dbEnv>"
    "<withSolr>false</withSolr>"
    "</ser:getUniqueNcidByRep>"
    "</soapenv:Body>"
    "</soapenv:Envelope>",
    "Snapshot=t1345500708.inf",    
    "ResponseParam=response",
    LAST);
    
        
    lr_end_transaction("HDD_IF_getUniqueNcidByRep", LR_AUTO);

I am getting this error:    

Action.c(20): Error: C interpreter run time error: Action.c (20):  Error -- Unresolved symbol : soap_request.

Could someone help me understand what went wrong in the script?

Thanks much!

Matt