Currency validation

Use jQuery for preliminary front-end validation. Then, at the server end, you could do something like

<cfif isDefined("form.someFieldname")>

    <cfset session.formSubmissionStatus = structNew()>

    <!--- Code to trim currencyField and strip off dollar sign  --->

    <cfset variables.currency = replace(trim(form.currencyField),"$","")>

    <cfif NOT isNumeric(variables.currency)>

        <cfset session.formSubmissionStatus.currencyField.value = variables.currency>

        <cfset session.formSubmissionStatus.currencyField.message = "Currency must be a numerical value.">

        <cflocation url="url-of-form-page">

    </cfif>

    <!--- Code to insert field(s) to database --->

</cfif>

If the server validation fails, the variables session.formSubmissionStatus.currencyField.value and session.formSubmissionStatus.currencyField.message will be available when the user is redirected to the form page. That enables you to inform the user that "Currency must be a numerical value.".

A more general, and better, validation technique is to give the responsibility of validating the entire form to a function. Something like

<cfif isDefined("form.someFieldname")>

     <cfset session.formSubmissionStatus = structNew()>

    <cfset session.formSubmissionStatus = validate(form)>

</cfif>

In the validate function, you will then validate each form field, storing each validation result a struct which you finally return.