html input=text max number 50 code example
Example: simple way to make a text field to accept numbers only with maximum number of length 13 digit and min 10
<input name="phoneNumber"
oninput="javascript: if (this.value.length > this.maxLength) this.value = this.value.slice(0, this.maxLength);"
type = "number"
maxlength = "10"
/>