Help with simple java script

[laks]

I am using following java script in one of my report. It works fine when I open in Report Studio, but its not working when I used in pagelet.

<button title="Pareto by Checklist" onclick="fW.elements['p_pTabToShow'].value='Checklist'; fW.elements['p_pChartsToShow'].value='Number'; SetPromptControl('Finish')" style="border-topstyle:none;border-left-style:none;border-right-style:none;borderbottom-style:none;display:block;background-color:white">Pareto by Checklist</button>

Suggestions Plz..