i have found one solution. :)

in html javascript file, first convert the uploaded image to base64 image format using following code.

var p;

var canvas = document.createElement(canvas);

var img1=document.createElement(img); 



function getBase64Image(){     

    p=document.getElementById(fileUpload).value;

    img1.setAttribute('src', p); 

    canvas.width = img1.width; 

    canvas.height = img1.height; 

    var ctx = canvas.getContext(2d); 

    ctx.drawImage(img1, 0, 0); 

    var dataURL = canvas.toDataURL(image/png);

    alert(from getbase64 function+dataURL );    

    return dataURL;

} 

so we got base64 code of uploaded image in dataURL.

NOW SEND THIS BASE64 CODE (dataURL) to web service and convert the base64 string to byte array using following code and save to sql server too

c# code--for converting base64 to byte arry and to store on sql

private void Form1_Load(object sender, EventArgs e) {

    int userid = 5;

    string base64=;// load base 64 code to this variable from js 

    Byte[] bitmapData = new Byte[base64.Length];

    bitmapData = Convert.FromBase64String(FixBase64ForImage(base64));

    string connstr = @user id=sa; password=*****; 

    database=ImageTest; 

    server=192.168.1.104;

    SqlConnection conn = new SqlConnection(connstr);

    conn.Open();

    string query;

    query = insert into imagetable(userid,image) values( + userid + , +  @pic);

    SqlParameter picparameter = new SqlParameter();

    picparameter.SqlDbType = SqlDbType.Image;

    picparameter.ParameterName = pic;

    picparameter.Value = bitmapData;

    SqlCommand cmd = new SqlCommand(query, conn);

    cmd.Parameters.Add(picparameter);

    cmd.ExecuteNonQuery();

    cmd.Dispose();

    conn.Close();

    conn.Dispose();

}

public static string FixBase64ForImage(string image) {

    StringBuilder sbText = new StringBuilder(image, image.Length);

    sbText.Replace(rn, String.Empty);

    sbText.Replace( , String.Empty);

    return sbText.ToString();

}

hope u understand :) ......