#62 - Add check for negative amounts

res/zec_qt_wallet_de.ts

@@ -643,6 +643,11 @@ doesn&apos;t look like a z-address</source>
         <source> is Invalid</source>
         <translation type="unfinished">YOUR_TRANSLATION_HERE</translation>
     </message>
+    <message>
+        <location filename="../src/sendtab.cpp" line="650"/>
+        <source>Amount &apos;%1&apos; is invalid!</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>MemoDialog</name>

res/zec_qt_wallet_es.ts

@@ -643,6 +643,11 @@ doesn&apos;t look like a z-address</source>
         <source> is Invalid</source>
         <translation> es Inválida</translation>
     </message>
+    <message>
+        <location filename="../src/sendtab.cpp" line="650"/>
+        <source>Amount &apos;%1&apos; is invalid!</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>MemoDialog</name>

res/zec_qt_wallet_fr.ts

@@ -646,6 +646,11 @@ Cette adresse ne semble pas être de type adresse-z</translation>
         <source> is Invalid</source>
         <translation> est invalide</translation>
     </message>
+    <message>
+        <location filename="../src/sendtab.cpp" line="650"/>
+        <source>Amount &apos;%1&apos; is invalid!</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>MemoDialog</name>

res/zec_qt_wallet_pt.ts

@@ -645,6 +645,11 @@ não se parece com um z-Address</translation>
         <source> is Invalid</source>
         <translation> é Inválido</translation>
     </message>
+    <message>
+        <location filename="../src/sendtab.cpp" line="650"/>
+        <source>Amount &apos;%1&apos; is invalid!</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>MemoDialog</name>

src/sendtab.cpp

@@ -643,8 +643,15 @@ QString MainWindow::doSendTxValidations(Tx tx) {
             QString addr = (toAddr.addr.length() > 100 ? toAddr.addr.left(100) + "..." : toAddr.addr);
             return QString(tr("Recipient Address ")) % addr % tr(" is Invalid");
         }
+
+        // This technically shouldn't be possible, but issue #62 seems to have discovered a bug
+        // somewhere, so just add a check to make sure. 
+        if (toAddr.amount < 0) {
+            return QString(tr("Amount '%1' is invalid!").arg(toAddr.amount));
+        }
     }
 
+
     return QString();
 }