--- a/configure.ac	Sat Nov 13 14:38:06 2010 -0500
+++ b/configure.ac	Thu Nov 18 14:22:04 2010 -0500
@@ -6,8 +6,20 @@
 AC_CONFIG_MACRO_DIR([m4])
 AC_CONFIG_HEADERS([config.h])
 
-AC_CHECK_LIB(mhash, mhash_get_block_size, [], [echo "You must install libmhash."; exit 1])
-AC_CHECK_HEADER([mhash.h], [], [echo "You must install libmhash dev files."; exit 1])
+dnl Setting the search directory for mhash.
+AC_ARG_WITH(mhash-dir, AS_HELP_STRING([--with-mhash-dir=DIR], [mhash directory; default = /usr]), 
+                          with_mhash_dir="$withval", with_mhash_dir="/usr")
+
+dnl Check for libmhash
+LIBS_save="$LIBS"
+LIBS="-L${with_mhash_dir}/lib/ -lmhash"
+AC_CHECK_LIB(mhash, mhash_get_block_size, 
+                    [MHASH_LIB_DIR="${with_mhash_dir}/lib"], [echo "You must install libmhash."; exit 1])
+LIBS="${LIBS_save}"
+
+dnl Check for mhash.h
+AC_CHECK_HEADER(["${with_mhash_dir}/include/mhash.h"],
+        [CPPFLAGS="${CPPFLAGS} -I${with_mhash_dir}/include"], [echo "You must install libmhash dev files."; exit 1])
 
 AC_CHECK_PROG(MLTON, mlton, yes, [])
 
@@ -55,6 +67,7 @@
 AC_SUBST(INCLUDE)
 AC_SUBST(SITELISP)
 AC_SUBST(GCCARGS)
+AC_SUBST(MHASH_LIB_DIR)
 
 AC_CONFIG_FILES([
         Makefile
@@ -67,9 +80,10 @@
 cat <<EOF
 
 Ur/Web configuration:
-  bin directory:       BIN       $BIN
-  lib directory:       LIB       $LIB
-  include directory:   INCLUDE   $INCLUDE
-  site-lisp directory: SITELISP  $SITELISP
-  Extra GCC args:      GCCARGS   $GCCARGS
+  bin directory:       BIN            $BIN
+  lib directory:       LIB            $LIB
+  include directory:   INCLUDE        $INCLUDE
+  site-lisp directory: SITELISP       $SITELISP
+  mhash lib directory: MHASH_LIB_DIR  $MHASH_LIB_DIR
+  Extra GCC args:      GCCARGS        $GCCARGS  
 EOF