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CompareValidator

The CompareValidator control compares the value of one control to another, or to an explicit value in the control's ValueToCompare property.

Note: For the purpose of validation, a specific property on the control is designated as its "value". For more information, see the Validating Form Inputs section.

CompareValidator uses three key properties to perform its validation. ControlToValidate and ControlToCompare contain the values to compare. Operator defines the type of comparison to perform, for example, Equal or Not Equal. CompareValidator performs the validation by evaluating these properties as an expression, as shown in the following example.

<ControlToValidate> <Operator> <ControlToCompare>

If the expression evaluates true, the validation result is valid.

The following sample illustrates using the CompareValidator control.

For a detailed discussion of Web Forms validation, please see the Validating Form Input Controls section of this QuickStart tutorial.