index.js
function(req, res, runMethod) {
    var form = new formidable.IncomingForm()
        ,files = {}
        ,fields = {}
        ,size = 0                

    for(var i in formConfig) {
        form[i] = formConfig[i]
    }
    form.on('file', function(field, file) {
        size += file.size
        if(size > maxUploadSize) {
            return false;
        }
        if(files[field]) {
            if(!util.isArray(files[field])) files[field] = [files[field]]                    
            files[field].push(file)        
        } else {
            files[field] = file;
        }
    })            
    form.on('field', function(field, value) {
        if(fields[field]) {
            if(!util.isArray(fields[field])) fields[field] = [fields[field]]                    
            fields[field].push(value)        
        } else {
            fields[field] = value;
        }
    })            
    form.on('end', function() {
        fields.files = files
        runMethod(req, res, fields); 
    });
    form.parse(req); 
}
function(req, res, runMethod) {
    var form = new formidable.IncomingForm()
        ,files = {}
        ,fields = {}
        ,size = 0                

    for(var i in formConfig) {
        form[i] = formConfig[i]
    }
    form.on('file', function(field, file) {
        size += file.size
        if(size > maxUploadSize) {
            return false;
        }
        if(files[field]) {
            if(!util.isArray(files[field])) files[field] = [files[field]]                    
            files[field].push(file)        
        } else {
            files[field] = file;
        }
    })            
    form.on('field', function(field, value) {
        if(fields[field]) {
            if(!util.isArray(fields[field])) fields[field] = [fields[field]]                    
            fields[field].push(value)        
        } else {
            fields[field] = value;
        }
    })            
    form.on('end', function() {
        fields.files = files
        runMethod(req, res, fields); 
    });
    form.parse(req); 
}
Create multipart parser to parse given request