asp.net web design_html/css_WEB-ITnose

I have recently come into contact with web design, please give me some advice. I implemented the following web page model. The web page consists of three parts. The logo designed by myself is embedded in the top part. The bottom part is divided into two columns. The navigation buttons are placed on the left side, and different content is displayed on the right side according to the user's selection. I hope that when the browser size changes, the size of the top part of the logo remains unchanged, and pictures that cannot be displayed by the browser are directly hidden without displaying scroll bars. The two columns in the lower part can display corresponding scroll bars in the vertical direction according to changes in browser size. Please give me some advice?

Reply to the discussion (solution)

<frameset rows="100,*"><frame src="top.aspx" frameborder=0 scrolling=no/><frameset cols="180,*"><frame src="menu.aspx"  frameborder=0 scrolling=no/><frame name="fmain" src="xxx.aspx"  frameborder=0 scrolling=no/></frameset></frameset>

Well, thank you, the solution is feasible. But let me ask again, can the src of the html control be switched dynamically? The code I wrote like this doesn't work.
System.Timers.Timer timer = new System.Timers.Timer();
private static int count;
protected void Page_Load(object sender, EventArgs e)
{
count = 0 ;
               Picture();                              r.AutoReset = true;
timer.Enabled = true;
timer.Interval = 5000;
timer.Elapsed = new System.Timers.ElapsedEventHandler(this.Picture_Show);
}
protected void Picture_Show(Object sender, ElapsedEven tArgs e)
{
count = (count 1) % 6;
switch (count)
{
case 0: this.imgkt.Src = this.imgkt.ResolveClientUrl("image/ UPS.jpg") ;
break;
case 1: this.imgkt.Src = this.imgkt.ResolveClientUrl("image/power meter.jpg" "?temp=" DateTime.Now.Millisecond.ToString());
              break; this.imgkt.Src = this.imgkt .ResolveClientUrl("image/access control.jpg");
break;
case 4: this.imgkt.Src = this.imgkt.ResolveClientUrl("image/leaking.jpg");
break;
         case 5: this.imgkt.Src = this.imgkt.ResolveClientUrl("image/Temperature and Humidity.jpg"); break;
}
}
protected void Picture()
{
this.imgkt.Src = this.imgkt.ResolveClientUrl("image/水水.jpg");
}
Please give me some advice on how to write the code Only in this way can the dynamic switching of img background be realized.