disable next btn if amount is 0

app/src/main/java/com/mob/utsmyanmar/ui/input_amount/InputAmountScreen.kt

@@ -171,16 +171,16 @@ fun InputAmount(
                         Text("Cancel")
                     }
 
+                    val isAmountValid = amount.toDoubleOrNull()?.let { it > 0.0 } == true
+
                     Button(
                         onClick = {
-                            if (amount.isNotEmpty()) {
                             onChargeClick(amount)
-                            }
                         },
                         modifier = Modifier
                             .weight(1f)
                             .height(56.dp),
-                        enabled = amount.isNotEmpty(),
+                        enabled = isAmountValid,
                         shape = RoundedCornerShape(8.dp),
                         colors = ButtonDefaults.buttonColors(
                             containerColor = Color.LegacyRed,