...
Response Field to check: Body
Reference Name: VIEWSTATE Regular Expression: id="_VIEWSTATE" value="(\[\\w/-_\].+)" Wiki Markup
Template: $1$
Match No. : 1
Default Value: NOT FOUND
Response Field to check: Body
Reference Name: EVENTVALIDATIONunmigrated-wiki-markup
Regular Expression: id="_EVENTVALIDATION" value="(\[\\w/-_\].+)"
Template: $1$
Match No. : 1
Default Value: NOT FOUND
Then in order to ensure these extracted values are passed in subsequent HTTP requests, for each request specify the following to be the Send Parameters for the Request:
Name: _VIEWSTATE
Value: ${VIEWSTATE}
Name: _EVENTVALIDATION
Value: ${EVENTVALIDATION}
...