Question

I have a form that you enter data into and it performs a calculation on it and give an answer. what i want to do is for it to keep the data in the form so that you can quickly repost so that you don’t have to change all the data. but I cant keep coming up with the error of it not existing, which I suppose is correct until the form has been posted!

@{
  var total = 0m;
  var totalMessage = "";


    if (IsPost)
    {
        var age = Request["frmage"].AsInt(0);
        var weight = Request["frmweight"].AsDecimal();
        var SerCre = Request["frmSerCre"].AsDecimal();
        var sexfactor = Request["frmGender"]== "M" ? 1.23m : 1.04m;

        total =Convert.ToDecimal ((((140 - age)*weight)* sexfactor )/SerCre ) ;

        totalMessage =  total.ToString("0.00") + "(ml/min) ";
    }


}
<div class="memberRegistration">
<form method="post">

<p>
    <label class="formLabel">Age:</label> in years
    <input class="formTextField" type="text" name="frmAge" size="3" value="@age"/>
</p>
<p>
    <label class="formLabel">Weight:</label> in Kg (1st = 6.35kg)
    <input class="formTextField" type="text" name="frmWeight" value="@weight"/>
</p>
<p>
    <label class="formLabel">Serum Creatinine:</label> in μmol/L
    <input class="formTextField" type="text" name="frmSerCre" value="@SerCre"/>

</p>
<p>

<label class="fieldLabel">Gender:</label>
    <select name="frmGender" id="select" value="@sexfactor">
        <option value="M">Male</option>
        <option value="F">Female</option>
    </select>

</p>
<p><input type="submit" value="Calculate" /></p>
</form>
<p>Calculated creatinine clearance <b>@totalMessage</b></p>
</div>

Answer 1

Try this

var age = 0;

    if (IsPost)
    {
        age = Request["frmage"].AsInt(0);

    }

<input class="formTextField" type="text" name="frmAge" size="3" value="@age"/>

---

But normally it would be better to use a model to hold your values, then in your controller you pass those values back again to your form