How to find a string from previous teststep response?

Hi All,

I need to search a string from previous teststep response. What I did is

def holder1 = groovyUtils.getXmlHolder( "teststep1#Response" )
def root = new XmlSlurper().parseText(holder1)

but I can't able to find the string that I needed in root

if(root.contains(string))

above if condition fails

how to achieve this any help is appreciated