Mine

--- configure.in	2006-10-25 11:28:00.000000000 -0500
+++ configure.in-new	2006-10-25 11:45:25.000000000 -0500
@@ -12,6 +12,7 @@
 
 build_python=0
 use_firefox=0
+use_seamonkey=0
 
 AC_ARG_ENABLE([python],
               AS_HELP_STRING([--enable-python],
@@ -21,6 +22,10 @@
               AS_HELP_STRING([--enable-firefox],
                              [build against Firefox instead of Mozilla]),
               [use_firefox="$enableval"])
+AC_ARG_ENABLE([seamonkey],
+              AS_HELP_STRING([--enable-seamonkey],
+                             [build against Seamonkey instead of Mozilla]),
+              [use_seamonkey="$enableval"])
 
 AM_INIT_AUTOMAKE
 AM_MAINTAINER_MODE
@@ -113,7 +118,7 @@
     else
     	MOZILLA_LIBS="$MOZILLA_LIBS -L$mozilla_libs/../lib -lembed_base_s"
     fi
-else
+elif
     if test "$use_firefox" = "yes" ; then
         PKG_CHECK_MODULES([MOZILLA], 
             [firefox-nspr >= 1.0 firefox-xpcom])
@@ -134,8 +139,30 @@
             MOZILLA_CFLAGS="$MOZILLA_CFLAGS $MOZILLA_GTK_CFLAGS"
             MOZILLA_LIBS="$MOZILLA_LIBS $MOZILLA_GTK_LIBS"
         fi
+else
+    if test "$use_seamonkey" = "yes" ; then
+        PKG_CHECK_MODULES([MOZILLA], 
+            [seamonkey-nspr >= 1.0 seamonkey-xpcom])
+        mozilla_includes=`$PKG_CONFIG --variable=includedir seamonkey-xpcom`
+        mozilla_libs=`$PKG_CONFIG --variable=libdir seamonkey-xpcom`
+        if test $USE_WXGTK = "yes"; then
+            PKG_CHECK_MODULES([MOZILLA_GTK], [seamonkey-gtkmozembed >= 1.0])
+            MOZILLA_CFLAGS="$MOZILLA_CFLAGS $MOZILLA_GTK_CFLAGS"
+            MOZILLA_LIBS="$MOZILLA_LIBS $MOZILLA_GTK_LIBS"
+        fi
+    else
+        PKG_CHECK_MODULES([MOZILLA], 
+            [mozilla-nspr >= 1.3 mozilla-xpcom])
+        mozilla_includes=`$PKG_CONFIG --variable=includedir mozilla-xpcom`
+        mozilla_libs=`$PKG_CONFIG --variable=libdir mozilla-xpcom`
+        if test $USE_WXGTK = "yes"; then
+            PKG_CHECK_MODULES([MOZILLA_GTK], [mozilla-gtkmozembed >= 1.3])
+            MOZILLA_CFLAGS="$MOZILLA_CFLAGS $MOZILLA_GTK_CFLAGS"
+            MOZILLA_LIBS="$MOZILLA_LIBS $MOZILLA_GTK_LIBS"
+        fi
     fi
 fi
+
 dnl Additional mozilla settings:
 if test "x$MOZILLA_HOME" = "x"; then
     MOZILLA_HOME=$mozilla_libs