diff --git a/src/Corporation/Actions.ts b/src/Corporation/Actions.ts
index ab217d843..03f937e08 100644
--- a/src/Corporation/Actions.ts
+++ b/src/Corporation/Actions.ts
@@ -119,17 +119,17 @@ export function SellMaterial(mat: Material, amt: string, price: string): void {
     try {
       tempQty = eval(tempQty);
     } catch (e) {
-      throw new Error("Invalid value or expression for sell price field: " + e);
+      throw new Error("Invalid value or expression for sell quantity field: " + e);
     }
 
     if (tempQty == null || isNaN(parseFloat(tempQty)) || parseFloat(tempQty) < 0) {
-      throw new Error("Invalid value or expression for sell price field");
+      throw new Error("Invalid value or expression for sell quantity field");
     }
 
     mat.sllman[0] = true;
     mat.sllman[1] = q; //Use sanitized input
   } else if (isNaN(parseFloat(amt)) || parseFloat(amt) < 0) {
-    throw new Error("Invalid value for sell quantity field! Must be numeric or 'MAX'");
+    throw new Error("Invalid value for sell quantity field! Must be numeric or 'PROD' or 'MAX'");
   } else {
     let q = parseFloat(amt);
     if (isNaN(q)) {
@@ -156,10 +156,10 @@ export function SellProduct(product: Product, city: string, amt: string, price:
     try {
       temp = eval(temp);
     } catch (e) {
-      throw new Error("Invalid value or expression for sell quantity field: " + e);
+      throw new Error("Invalid value or expression for sell price field: " + e);
     }
     if (temp == null || isNaN(parseFloat(temp)) || parseFloat(temp) < 0) {
-      throw new Error("Invalid value or expression for sell quantity field.");
+      throw new Error("Invalid value or expression for sell price field.");
     }
     product.sCost = price; //Use sanitized price
   } else {
@@ -184,11 +184,11 @@ export function SellProduct(product: Product, city: string, amt: string, price:
     try {
       temp = eval(temp);
     } catch (e) {
-      throw new Error("Invalid value or expression for sell price field: " + e);
+      throw new Error("Invalid value or expression for sell quantity field: " + e);
     }
 
     if (temp == null || isNaN(parseFloat(temp)) || parseFloat(temp) < 0) {
-      throw new Error("Invalid value or expression for sell price field");
+      throw new Error("Invalid value or expression for sell quantity field");
     }
     if (all) {
       for (let i = 0; i < cities.length; ++i) {
@@ -201,7 +201,7 @@ export function SellProduct(product: Product, city: string, amt: string, price:
       product.sllman[city][1] = qty; //Use sanitized input
     }
   } else if (isNaN(parseFloat(amt)) || parseFloat(amt) < 0) {
-    throw new Error("Invalid value for sell quantity field! Must be numeric");
+    throw new Error("Invalid value for sell quantity field! Must be numeric or 'PROD' or 'MAX'");
   } else {
     let qty = parseFloat(amt);
     if (isNaN(qty)) {