Script to convert spaces in filename to underscores

#!/bin/bash 
IFS=' 
' 
j=`find $1 -printf "%d\n" | sort -u | tail -n 1`  
echo "Max dir depth:" $j 
for (( i=0; i<=j ; i++ )) 
do 
  for name in `find -mindepth $i -maxdepth $i -iname "* *" -printf "%p\n"` 
  do 
    newname=`echo "$name" | tr " " "_"` 
    echo "$name" "$newname" 
    mv "$name" "$newname" 
  done 
done