How to overcome pop up shile replaying recorded Selenium IDE

I recorded application in selenium IDE HTML format after replaying this is the error that is displaying "Firefox prevented this site fr开发者_Go百科om opening pop up window"

 In selenium IDE in log we got error like this "[warn] Opening window '_blank', which is not a real window name. Randomizing target to be: selenium_blank54652" 

  how do i solve this problem?

Give that window a name, example:

window.open('url', 'name_here', 'more_options');