Initial page of CS8802 error

docs/csharp/language-reference/compiler-messages/cs8802.md

@@ -0,0 +1,49 @@
+---
+description: "Compiler Error CS8802"
+title: "Compiler Error CS8802"
+ms.date: 7/01/2024
+f1_keywords:
+  - "CS8802"
+helpviewer_keywords:
+  - "CS8802"
+---
+# Compiler Error CS8802
+
+Only one compilation unit can have top-level statements.
+
+This error indicates that there are two or more [top-level statements](../../fundamentals/program-structure/top-level-statements.md) in a single compilation unit (single solution, project or a single group of files compiled into a single binary file).
+
+## Example
+
+The following sample of single compilation unit generates CS8802:
+
+```xml
+<!-- SingleCompilationUnit.csproj -->
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+  </PropertyGroup>
+</Project>
+```
+
+```csharp
+// EntryFile.cs
+
+int a = 0;
+```
+
+```csharp
+// SecondaryEntryFile.cs
+
+int b = 1;    // CS8802: The top level statement already exists in EntryFile.cs
+```
+
+## To correct this error
+
+Use only one top-level statement in the project.
+<br/>Top-level statements acts as an entry point to the program, so only one file may have top-level statement. All other statements must be defined as members of classes or structs.
+
+## See also
+
+- [Top-level statements](../../fundamentals/program-structure/top-level-statements.md)
+- [CS8803](./cs8803.md)