M4 airsoft gun will not shoot straight.?

I turned the hop all the way up on my M4 airsoft gun and instead of shooting straighter, it goes directly UP on leaving the barrel. How do i turn the hop back to norm. The hop switch goes to the left, and eventually stopped at the limit, and it will not turn back. Here is my gun: a href="http://www.google.com/imgres?imgurl=http://www.elec-intro.com/EX/05-14-17/m14-airsoft-sniper-rifle-airsoft.jpg&imgrefurl=http://beautiful-views.com/airsoft-m14.html&usg=__yDirJ5WlsQmU8pYEm12FB6dTFzw=&h=400&w=400&sz=9&hl=en&start=0&sig2=9UMethGSHnB62azSlvaGnQ&zoom=1&tbnid=8jV-_GawdV-eJM:&tbnh=150&tbnw=150&ei=c3RlTcaPJc-TtwfJ3umYBg&prev=/images%3Fq%3DM14%2Bairsoft%26um%3D1%26hl%3Den%26client%3Dfirefox%26sa%3DN%26rls%3Dcom.yahoo:en-US:official%26biw%3D922%26bih%3D493%26tbs%3Disch:1&um=1&itbs=1&iact=hc&vpx=131&vpy=122&dur=2527&hovh=225&hovw=225&tx=117&ty=112&oei=c3RlTcaPJc-TtwfJ3umYBg&page=1&ndsp=8&ved=1t:429,r:0,s:0" rel="nofollow"http://www.google.com/imgres?imgurl=http…/a