/* * File: checkForm.js * * Automatic form checking (for ver 4.0 browsers and above) * * Usage: * * * ... *

* * Insert the * * ... * * * where mailTo, mailFrom, mailSubject, group, and message are the * names of specific input elements that require checking (all other * input elements are ignored). * * Here is a complete list of the functions called by checkForm(): * * Element Function * ------------------------------------------------------------------ * text checkText * textarea checkTextarea * radio checkRadio * checkbox checkCheckbox * select-one checkSelectOne * select-multiple checkSelectMultiple * file checkFile * password checkPassword * * These boolean functions may be used separately (as above) or may be * overridden for further customization. For example, here's how to * use a more restrictive form of the checkSelectMultiple() function: * * * * ... * * * Finally, here is an example that handles select elements with * attribute SIZE="1" (which is the default size in HTML): * * * * ... * * * The checkSelectSpecial() function returns true if the user * makes a selection other than options[0]. * */ // Returns true if all form elements pass their respective test: function checkForm( formObj ) { // Local variables: var element, type, name, oldName; // Check all input elements: var n = formObj.elements.length; for ( var i = 0; i < n; i++ ) { element = formObj.elements[i]; type = element.type; // Ignore buttons and hidden fields: if ( type == "text" ) { if ( !checkText( element ) ) return false; } else if ( type == "textarea" ) { if ( !checkTextarea( element ) ) return false; } else if ( type == "radio" || type == "checkbox" ) { name = element.name; if ( name != oldName ) { // Obtain the corresponding group element: element = eval( "formObj." + name ); if ( type == "radio" && !checkRadio( element ) ) return false; if ( type == "checkbox" && !checkCheckbox( element ) ) return false; oldName = name; } } else if ( type == "select-one" ) { if ( !checkSelectOne( element ) ) return false; } else if ( type == "select-multiple" ) { if ( !checkSelectMultiple( element ) ) return false; } else if ( type == "file" ) { if ( !checkFile( element ) ) return false; } else if ( type == "password" ) { if ( !checkPassword( element ) ) return false; } } // All tests were successful: return true; } // Default function assignments: var checkText = checkTextGeneric; var checkTextarea = checkTextGeneric; var checkFile = checkTextGeneric; var checkPassword = checkTextGeneric; var checkSelectOne = checkSelectGeneric; var checkSelectMultiple = checkSelectGeneric; // Returns true if a generic text element is not empty: function checkTextGeneric( textObj ) { if ( isEmpty( textObj ) ) { window.alert( "Enter " + textObj.name + "!" ); textObj.value = ""; textObj.focus(); return false; } return true; } // Returns true if an option of a generic select element is selected // or if the user does not wish to select any options: function checkSelectGeneric( selectObj ) { if ( selectObj.selectedIndex == -1 ) { var name = selectObj.name; if ( window.confirm( "Do you want to select " + name + "?" ) ) { selectObj.focus(); return false; } } return true; } // Returns true if a radio button is checked: function checkRadio( radioObj ) { var n = radioObj.length; for ( var i = 0; i < n; i++ ) { if ( radioObj[i].checked ) return true; } window.alert( "Please check " + radioObj[0].name + "!" ); radioObj[0].focus(); return false; } // Returns true if at least one of a group of checkboxes is checked // or if the user does not wish to check any checkboxes: function checkCheckbox( checkboxObj ) { var n = checkboxObj.length; for ( var i = 0; i < n; i++ ) { if ( checkboxObj[i].checked ) return true; } var name = checkboxObj[0].name; if ( window.confirm( "Do you want to check " + name + "?" ) ) { checkboxObj[0].focus(); return false; } return true; } // Returns true if an option is selected: function checkSelectStrict( selectObj ) { if ( selectObj.selectedIndex == -1 ) { window.alert( "Please select " + selectObj.name + "!" ); selectObj.focus(); return false; } return true; } // A function to check select elements with attribute SIZE="1". // Returns true if the user makes a selection other than options[0]: function checkSelectSpecial( selectObj ) { if ( selectObj.selectedIndex == 0 ) { window.alert( "Please select " + selectObj.name + "!" ); selectObj.focus(); return false; } return true; } // Returns true if the value of the text element is null or whitespace: function isEmpty( textObj ) { var regexp = /^\s*$/; return regexp.test( textObj.value ); } // For backwards compatibility with a previous version of this script: // (Do not use! Will be removed in a future version!) var checkSelect = checkSelectSpecial;