throws error on insufficient fund

src/wallet.js

@@ -203,6 +203,8 @@ var Wallet = function (seed, options) {
           break;
         }
 
+        checkInsufficientFund(totalInValue, value, fee)
+
         this.sign(tx)
 
         return tx
@@ -214,6 +216,13 @@ var Wallet = function (seed, options) {
       }
     }
 
+    function checkInsufficientFund(totalInValue, value, fee) {
+      if(totalInValue < value + fee) {
+        throw new Error('Not enough money to send funds including transaction fee. Have: ' +
+                        totalInValue + ', needed: ' + (value + fee))
+      }
+    }
+
     function estimateFeePadChangeOutput(tx){
         var tmpTx = tx.clone()
         tmpTx.addOutput(getChangeAddress(), 0)