c
      subroutine sltxax(glonl,glonr,ut,vp,yoffset)
c
c Add local time axis to existing longitude axis, at given ut
c Existing lon axis range is glonl (left) to glonr (right)
c (glonl,glonr given in the range -180. to 180.)
c This is usually called with glonl=glonr meaning 360 degrees longitude
c   is being plotted, but it should work with narrower range of lons.
c
      character*8 str
      character*32 xlab
      real vp(4)
      data nmjr/6/
      data xlab/'LOCAL TIME (HRS)                '/
c
c     write(6,"('enter sltxax: glonl=',f8.2,' glonr=',f8.2,' ut=',
c    +  f6.2,' yoffset=',f9.3,/' vp=',4f9.3)") glonl,glonr,ut,
c    +  yoffset,vp
c
c 12/95:
c Yoffset from user is fraction of viewport height.
c Chsize, ticlen, ynumoff are set as fractions of viewport width
c
c     yoff = .035
      yoff = .12
      if (yoffset.gt.0.) yoff = yoffset*(vp(2)-vp(1))
      chsize = .020*(vp(2)-vp(1))
      ticlen = .02*(vp(2)-vp(1))
      ynumoff = .05*(vp(2)-vp(1))
c
      glon0 = glonl+180.
      glon1 = glonr+180.
      dlon = glon1-glon0
      if (dlon.eq.0.) dlon = 360.
      if (dlon.lt.0.) dlon = glon1+(360.-glon0)
      dhrs = dlon/15.	! delta hours across axis
      slt0 = fslt(dum,ut,glonl,1)
      wlslt = slt0
      idel= int(dhrs)/nmjr	! delta hrs between major slt tics
      if (idel.le.0) idel = 1
      nmnr = idel
c
c Below error fixed 12/13/95:
c     if (slt0-ifix(slt0).ne.0.) slt0 = rnd(slt0,del)
      if (slt0-ifix(slt0).ne.0.) slt0 = rnd(slt0,float(idel))
c
      call getset(sl,sr,sb,st, wl,wr,wb,wt, log)
      call set(0.,1.,0.,1.,0.,1.,0.,1.,1)
      vl = vp(1)
      vr = vp(2)
      vb = vp(3)
      vt = vp(4)
      xpos0 = vl + (slt-wlslt)*(vr-vl)/dhrs
      xpos1 = vl + (slt+idel-wlslt)*(vr-vl)/dhrs
      dmnr = 1./nmnr * (xpos1-xpos0)
      yposax = vb-yoff
      call line(vl,yposax,vr,yposax)
      slt = slt0
      ypos = vb-yoff-ynumoff
      do i=1,100
        xpos = vl + (slt-wlslt)*(vr-vl)/dhrs
        if (xpos.lt.vl) goto 100
        if (xpos.gt.vr) goto 101
        call line(xpos,yposax,xpos,yposax+ticlen)
        call clearstr(str)
        sltlab = slt
        if (sltlab.ge.24.) sltlab = sltlab-24.
        write(str,"(f5.1)") sltlab
        call rmblnk(str)
        len = lenstr(str)
        call plchmq(xpos,ypos,str(1:len),chsize,0.,0.)
        call line(xpos,yposax,xpos,yposax+ticlen)
        do ii=1,nmnr-1
          xmnr = xpos-ii*dmnr
          if (xmnr.ge.vl.and.xmnr.le.vr) 
     +      call line(xmnr,yposax,xmnr,yposax+.5*ticlen)
        enddo         
 100    continue
        slt = slt+idel
      enddo 
 101  continue           
      call plchmq(0.5*(vl+vr),vb-yoff-2.2*ynumoff,xlab(1:lenstr(xlab)),
     +  chsize,0.,0.)
      call set(sl,sr,sb,st, wl,wr,wb,wt, log)
      return
      end
c