Changed Robot.txt File and Blog Not Showing Up In Search Results

Question: i tried to change robots.txt file of my blogspot blog and now its not showing up in search engines, how do i fix robots.txt file of my blogspot blog

As far as i can understand you changed your site's robot.txt file and its now showing up in any search results. First of all i must say that you should not change the robot.txt file of your site / blog unless you are completely sure about what you are doing . I suggest that you always use the default robot.txt file of your blog and never change it without any proper consultation. You can view your blog's robot.txt file at the following url by replacing "yoursite.com" with the name of your site .

yoursite.com/robots.txt

by default it should look like this :
User-agent: *
Disallow:
Allow: /

If you changed it then change it back to default by using the above mentioned robot.txt file . It should solve the problem if there is anything wrong with your robot.txt file .

Other reason your blog isn't showing up in any search results could be that it isn't indexed by search engines . Low quality blogs also don't show up on the first page of the search results so improve the quality of your blog to increase its search results presence.