hii every one

i have created a data entry screen like this in which each row contains a text field
![enter image description here](https://i.stack.imgur.com/FWfbi.png) 

here after entering data into the text field if we scroll the page which are all the text fields goesup(beyond the view) will set to null when it come back to the original position,, this is my code for each cell where `CustomCellStudentData` is a cell class where i have created frames for lables

```
- (UITableViewCell *)tableView:(UITableView *)tableView 
         cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    //static NSString *CellIdentifier = @"Cell";

    CustomCellStudentData *cell = (CustomCellStudentData*)[tableView dequeueReusableCellWithIdentifier:nil];

    if (cell == nil) {
      cell = [[[CustomCellStudentData alloc] initWithFrame:CGRectZero reuseIdentifier:nil] autorelease];
    }
    [cell setSelectionStyle:UITableViewCellSelectionStyleNone];

    switch(indexPath.section)
    { 
        case 0:
            switch (indexPath.row) 
            {
                case 0:
                {
                    tfText[0] = [[UITextField alloc] initWithFrame:CGRectMake(125,22, 170, 25)];
                    cell.accessoryView = tfText[0];
                    tfText[0].delegate=self;
                    tfText[0].font = [UIFont systemFontOfSize:14];
                    tfText[0].placeholder =@"<Student Name>";

                    cell.primaryLabel.text =@"Student Name: ";

                } 
                break;

                case 1: 
                {
                    tfText[1] = [[UITextField alloc] initWithFrame:CGRectMake(125,22, 170, 25)];
                    cell.accessoryView = tfText[1];
                    tfText[1].delegate=self;
                    tfText[1].font = [UIFont systemFontOfSize:14];
                    tfText[1].placeholder =@"<Student Age>";
                    tfText[1].keyboardType = UIKeyboardTypeNumbersAndPunctuation;
                   cell.primaryLabel.text =@"Student Age: ";
                } 
                break;

                case 2:
                {
                    cell.primaryLabel.text =@"Gender: ";

                    segmentedControl = [[UISegmentedControl alloc] initWithItems:nil];
                    segmentedControl.segmentedControlStyle = UISegmentedControlStylePlain;
                    segmentedControl.frame = CGRectMake(125,22, 170, 25);
                    [segmentedControl insertSegmentWithTitle:@"Male" atIndex:0 animated:YES];
                    [segmentedControl insertSegmentWithTitle:@"Female" atIndex:1 animated:YES];
                    segmentedControl.selectedSegmentIndex = 1;
                    [segmentedControl setMomentary:NO];
                    [segmentedControl addTarget:self action:@selector(segmentSwitch:) forControlEvents:UIControlEventValueChanged];
                    cell.accessoryView =segmentedControl;
                }
                break;

                case 3:
                {
                    tfText[3] = [[UITextField alloc] initWithFrame:CGRectMake(125,22, 170, 25)];
                    cell.accessoryView = tfText[3];
                    tfText[3].delegate=self;
                    tfText[3].font = [UIFont systemFontOfSize:14];
                    tfText[3].placeholder =@"<dd/mm/yyyy>";
                    tfText[3].keyboardType = UIKeyboardTypeNumbersAndPunctuation;
                    cell.primaryLabel.text =@"Date Of Birth: ";
                }
    }
}

```

y that data becoming null, how can i resolve this ,, can any one help me,,
thanx in advance