پاک کردن فرم با جاوا اسکریپت

// function will clear input elements on ever form on HTML page
    function clearForms() {
    // variable declaration
    var x, y, z, type = null;
    // loop through forms on HTML page
    for (x = 0; x < document.forms.length; x++) {
    // loop through each element on form
    for (y = 0; y < document.forms[x].elements.length; y++) {
    // define element type
    type = document.forms[x].elements[y].type;
    // alert before erasing form element
    //alert('form='+x+' element='+y+' type='+type);
    // switch on element type
    switch (type) {
    case 'text':
    case 'textarea':
    case 'password':
    //case "hidden":
    document.forms[x].elements[y].value = '';
    break;
    case 'radio':
    case 'checkbox':
    document.forms[x].elements[y].checked = '';
    break;
    case 'select-one':
    document.forms[x].elements[y].options[0].selected = true;
    break;
    case 'select-multiple':
    for (z = 0; z < document.forms[x].elements[y].options.length; z++) {
    document.forms[x].elements[y].options[z].selected = false;
    }
    break;
    } // end switch
    } // end for y
    } // end for x
    }
     
    As script goes through all form elements on the HTML page, it will not clear only this test form, but Search field and the Message box also. So if you want to leave a comment, do not test the Clear button before you click on submit. On the other hand, if you want to clear only group of input elements closed within DIV or some other HTML tag, you will have to modify clearForms() function and it can look like:
     
    function clearElements(el) {
    // variable declaration
    var x, y, z, type = null, object = [];
    // collect form elements
    object[0] = document.getElementById(el).getElementsByTagName('input');
    object[1] = document.getElementById(el).getElementsByTagName('textarea');
    object[2] = document.getElementById(el).getElementsByTagName('select');
    // loop through found form elements
    for (x = 0; x < object.length; x++) {
    for (y = 0; y < object[x].length; y++) {
    // define element type
    type = object[x][y].type;
    switch (type) {
    case 'text':
    case 'textarea':
    case 'password':
    object[x][y].value = '';
    break;
    case 'radio':
    case 'checkbox':
    object[x][y].checked = '';
    break;
    case 'select-one':
    object[x][y].options[0].selected = true;
    break;
    case 'select-multiple':
    for (z = 0; z < object[x][y].options.length; z++) {
    object[x][y].options[z].selected = false;
    }
    break;
    } // end switch
    } // end for y
    } // end for x
    }
    You will have to assign ID to the parent element which contains input elements. To clear input elements, function call should look clearElements('myForm').