border in tr HTML CSS ?

try this-

<tr style="outline: thin solid">

Way of tracking previous page asp.net ?

Try This ...

 

 

static string prev = String.Empty; 

 

protected void Page_Load(object sender, EventArgs e)

{

     if( !IsPostBack )

     {

         prev = Request.UrlReferrer.ToString();

     }

 

 }

 

 protected void btn_previous(object sender, EventArgs e)

 {

      Response.Redirect(prev);

 }

how to give height that fits the page css ?

Try this:

 

style="height: 100vh;"
 

or
 

html, body {height: 100%;}

or

body
{
padding:0px;
margin:0px;
width:100%;
height:100%;
}

how to stop last entry suggestion textbox in asp.net ?

try this:

autocomplete="off"

example: 

<asp:TextBox ID="TextBox1" runat="server" autocomplete="off"></asp:TextBox>

How to add a column using query MS SQL ?

 ALTER TABLE my_tbl ADD my_col varchar(50)


 to delete try this:
ALTER TABLE my_tbl DROP COLUMN my_col

textbox accept only numbers in javascript ?

<SCRIPT language=Javascript>
          function allow_num(num) {
        var charCode = (num.which) ? num.which : num.keyCode;
        if (charCode != 46 && charCode > 31
            && (charCode < 48 || charCode > 57))
            return false;

        return true;
    }

</SCRIPT>

call this function:

 <asp:TextBox ID="txt_num" onkeypress="return allow_num(event)" CssClass="txt" runat="server"></asp:TextBox>

 <input id="Text1" onkeypress="return allow_num(event)" type="text" />

Enable row number in visual studio for HTML and Back End codes?

On the menu bar, 
Click Tools, 
Then Options (in bottom). 
Expand the Text Editor node, 
Then the languages you are using, 
EG: C#, HTML 

You are then done here...