diff --git a/Operand.cpp b/Operand.cpp
index aee75f0..f24fb93 100644
--- a/Operand.cpp
+++ b/Operand.cpp
@@ -53,7 +53,16 @@ namespace jet {
 	 } else
 	   throw coreutils::Exception("Expecting ) at end of LEFT expression.");	 
       } else if(in.ifNextIgnoreCase("EXPR")) {
-	 
+	 if(!in.ifNext("("))
+	   throw coreutils::Exception("Expecting ( for LEFT parameters.");
+	 Operand parm1(in, global, lvariables);
+	 if(in.ifNext(")")) {
+	    Operand op(in, global, lvariables);
+	    string = op.string;
+	    isNumber = op.isNumber;
+	    boolean = op.boolean;	    
+	 } else
+	   throw coreutils::Exception("Expecting ) at end of EXPR expression.");	 	 
       } else if(in.ifNextIgnoreCase("RIGHT")) {
 	 
       } else if(in.ifNextIgnoreCase("TRIM")) {
@@ -90,7 +99,8 @@ namespace jet {
 	 string = in.getTokenExclude("'");
 	 in.ifNext("'");
 	 isNumber = false;
-      }
+      } else
+	throw coreutils::Exception("operand is not valid.");
 
       in.skipWhitespace();
       
@@ -284,7 +294,6 @@ namespace jet {
 	   throw coreutils::Exception("operand is not a number.");	 
       } else 
 	return;
-           
    }
    
 }
diff --git a/tests/testexpr.jet b/tests/testexpr.jet
new file mode 100755
index 0000000..220ae99
--- /dev/null
+++ b/tests/testexpr.jet
@@ -0,0 +1,6 @@
+#!../jet-2.0
+<jet name1="localname" filterblanklines="true" trimlines="true">
+<set name="test1" value="5 + 5" />
+<set name="test2" expr="expr($[test1])" />
+$[test2]
+</jet>
diff --git a/tests/testwhile.jet b/tests/testwhile.jet
index a3c3628..95b0e3a 100755
--- a/tests/testwhile.jet
+++ b/tests/testwhile.jet
@@ -1,8 +1,8 @@
 #!../jet-2.0
 <jet cgi="false" name1="localname" filterblanklines="true" trimlines="true">
  <set name="ix" value="1" />
- <while expr="$[ix]<=11">
+ <while expr="$[ix] <= 11">
   -->$[ix]<--
-  <set name="ix" expr="$[ix]+1" />
+  <set name="ix" expr="$[ix] + 1" />
  </while>
 </jet>