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The HTMLFormElement.length read-only property returns the number of controls in the <form> element.
integer = form.length
if (document.getElementById("form1").length > 1) {
// more than one form control here
}
HTMLFormElementBeforeUnloadEventDOMStringMapDataTransferDragEventErrorEventGlobalEventHandlersHTMLAnchorElementHTMLAreaElementHTMLAudioElementHTMLBRElementHTMLBaseElementHTMLBaseFontElementHTMLBodyElementHTMLButtonElementHTMLCanvasElementHTMLContentElementHTMLDListElementHTMLDataElementHTMLDataListElementHTMLDialogElementHTMLDivElementHTMLDocumentHTMLElementHTMLEmbedElementHTMLFieldSetElementHTMLFormControlsCollectionHTMLFrameSetElementHTMLHRElementHTMLHeadElementHTMLHeadingElementHTMLHtmlElementHTMLIFrameElementHTMLImageElementHTMLInputElementHTMLIsIndexElementHTMLKeygenElementHTMLLIElementHTMLLabelElementHTMLLegendElementHTMLLinkElementHTMLMapElementHTMLMediaElementHTMLMetaElementHTMLMeterElementHTMLModElementHTMLOListElementHTMLObjectElementHTMLOptGroupElementHTMLOptionElementHTMLOptionsCollectionHTMLOutputElementHTMLParagraphElementHTMLParamElementHTMLPictureElementHTMLPreElementHTMLProgressElementHTMLQuoteElementHTMLScriptElementHTMLSelectElementHTMLShadowElementHTMLSourceElementHTMLSpanElementHTMLStyleElementHTMLTableCaptionElementHTMLTableCellElementHTMLTableColElementHTMLTableDataCellElementHTMLTableElementHTMLTableHeaderCellElementHTMLTableRowElementHTMLTableSectionElementHTMLTextAreaElementHTMLTimeElementHTMLTitleElementHTMLTrackElementHTMLUListElementHTMLUnknownElementHTMLVideoElementHashChangeEventHistoryImageDataLocationMessageChannelMessageEventMessagePortNavigatorNavigatorGeolocationNavigatorIDNavigatorLanguageNavigatorOnLineNavigatorPluginsPageTransitionEventPluginPluginArrayPopStateEventRadioNodeListTransferableValidityStateWebVTTWindowWindowBase64WindowEventHandlersWindowTimers