# NextIfField.Expression1 Property

> Gets and sets the first expression text that should be compared. To use this field in the MailMerge component, this property must be a valid field name.

- **Product:** TX Text Control .NET for Windows Forms
- **Section:** Reference
- **Kind:** Property
- **Introduced:** 20.0
- **Namespace:** `TXTextControl.DocumentServer.Fields`
- **Package:** `TXTextControl.TextControl.WinForms.SDK` (assembly `TXDocumentServer.dll`, from the private NuGet feed or Text Control Offline Packages)
- **.NET Framework:** reference `TXDocumentServer.dll` from the setup
- **Path:** TX Text Control .NET for Windows Forms > Reference > TXTextControl.DocumentServer.Fields > NextIfField.Expression1 Property
- **Web URL:** https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol-documentserver-fields/nextiffield/expression1-property/
- **LLMs URL:** https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol-documentserver-fields/nextiffield/expression1-property/llms.txt
- **LLMs-Full URL:** https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol-documentserver-fields/nextiffield/expression1-property/llms-full.txt

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## On This Page

- [Description](https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol-documentserver-fields/nextiffield/expression1-property/#description)
- [Syntax](https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol-documentserver-fields/nextiffield/expression1-property/#syntax)
- [Examples](https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol-documentserver-fields/nextiffield/expression1-property/#examples)

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## Nearby

- **Previous:** [NextIfField.DataSourceCulture Property](https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol-documentserver-fields/nextiffield/datasourceculture-property/llms.txt)
- **Next:** [NextIfField.Expression2 Property](https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol-documentserver-fields/nextiffield/expression2-property/llms.txt)