Problem statement: It is necessary for me to write a code, whether which before form sending will check all necessary fields are filled. If not all fields are filled, it is necessary to allocate with their red colour and not to send the form.

Now the code exists in such kind:

function formsubmit(formName, reqFieldArr){     
    var curForm = new formObj(formName, reqFieldArr);
    if(curForm.valid)
        curForm.send();
    else
        curForm.paint();    
}


function formObj(formName, reqFieldArr){
    var filledCount = 0;
    var fieldArr = new Array();
    for(i=reqFieldArr.length-1; i>=0; i--){
        fieldArr[i] = new fieldObj(formName, reqFieldArr[i]);
        if(fieldArr[i].filled == true)
        filledCount++;
    }

    if(filledCount == fieldArr.length)
        this.valid = true;
    else
        this.valid = false;


    this.paint = function(){
        for(i=fieldArr.length-1; i>=0; i--){
            if(fieldArr[i].filled == false)
                fieldArr[i].paintInRed();
            else
                fieldArr[i].unPaintInRed();
        }
    }

    this.send = function(){
        document.forms[formName].submit();
    }
}


function fieldObj(formName, fName){
    var curField = document.forms[formName].elements[fName];

    if(curField.value != '')
        this.filled = true;
    else
        this.filled = false;

    this.paintInRed = function(){
        curField.addClassName('red');
    }

    this.unPaintInRed = function(){
        curField.removeClassName('red');
    }
}

Function is caused in such a way:

<input type="button" onClick="formsubmit('orderform', ['name', 'post', 'payer', 'recipient', 'good'])"  value="send" />

Now the code works. But I would like to add "dynamism" in it.

That it is necessary for me: to keep an initial code essentially, to add listening form fields (only necessary for filling).

For example, when the field is allocated by red colour and the user starts it to fill, it should become white.

As a matter of fact I need to add listening of events: onChange, blur for the blank fields of the form. As it to make within the limits of an initial code.

If all my code - full nonsense, let me know about it. As to me it to change using object-oriented the approach.